Follow this guide at your own risk. I've attempted to make it as straightforward as possible but can't promise that I've covered every detail. I hope it's helpful for some of you.
Okay, here we go.
Based on the Honda guide here: Install Parking Sensors
I thought I'd have a bash at installing them.
These were the ones I bought: CISBO Parking Reversing Sensor 4 Sensors Audio Buzzer | eBay
and having a Milano car I opted for the bright red option. The colour isn't perfect (and in the photos below looks terrible) but is certainly good enough for me when they're on the car. As per other threads, there's always the option of painting them yourself but quite honestly I wasn't that fussed as it's close enough.
FIRST - FIND A 12V SUPPLY IN YOUR HOUSE AND TEST THE SENSORS. You do NOT want to go through the below to find they don't work.
The one thing I would really recommend is taking your time. If you don't then something will get broken or damaged and it's just not worth rushing it. This took me about 6 hours to do over 2 days, so keep that in mind! Hopefully with this guide it should take you a bit less... the Honda guide is a bit short on explanation. The second thing I would recommend is plenty of cups of tea!
Getting the bumper off.
Remove the four coloured caps and loosen off (but don't remove) the bolts as can be seen on the photo below
Next, the push-pins on the bottom. There are four on each side (if none have fallen out...) but you should NOT remove the middle two
as these are only for holding on the exhaust trim and you'll just be wasting your time - as I discovered the hard way. The second pin to remove is just off to the right of the photo, and you can see in the photo below the holes where they were attached.
Before removing the arch, there's a retaining screw to be released; and that's here
A bit of a pain to get to because of the rear wheel, but with a long screwdriver it's accessible without too much difficulty. Just be careful not to destroy the screwhead.
With that done, we move to the side arches. With the push pins and screw removed, start at the back of the arch and gently but firmly pull away at the arch to remove it. Make sure you apply even pressure over the clips lest you break one. I was fairly aggressive with mine and they stayed attached but I've broken clips elsewhere with far less force! Keep going until you reach the break in the bumper next to the retaining screw
and remove it
(already removed in this photo).
The next part is the most tricky and that's mainly because it's difficult to assess how much force to use.
The bumper needs to be pushed forwards and pulled outwards at the same time to release the clips.
The following two photos show the car and bumper sections that meet after removal to help give you a better idea of how they fit together.
Looking at the following photo, grip the bumper where you removed the retaining screw, and push it forwards then pull it out.
This should release the bottom clip, and you'll then see how it goes for the rest (i.e. rinse and repeat).
Having not undone the 4 bolts that were under the caps before, you can leave the bumper unclipped on this side and then do the same on the other side.
Place some cardboard underneath the area where the bumper is, and then undo the 4 bolts. The bumper should stay attached even with these removed, and you'll need to hold it in the middle and pull it away from the car to release. It came away rather suddenly for me and thankfully fell onto the cardboard I'd placed down (hence my recommendation) - otherwise I'd have damaged the paint!
With the bumper off, place it down and look on the inside for the pilot hole markings. They're fairly faint, and look like a circle with a "+" inside. Obviously your pilot hole goes on the intersection of the cross! I had to clean off the inside of my bumper to make them visible - rather foolishly I didn't take any photos but look closely and you'll see what I mean.
Drill your pilot hole from the inside to the outside, and then use the supplied hole-saw to drill from the outside to the inside. This means that the outside edge is neater - just remember to undo the chuck and collect the hole-saw from the other side; don't pull it back through else you'll pull some paint off with it.
Apply the adjustment rings to your sensors (if you don't need them, it's easier to cut it off than to take off the bumper again to apply it...) and put them through the hole you made. I drilled into the plastic tabs on the inside of my bumper to make holes for cable ties just so the cables wouldn't touch the exhaust triangles or snag anywhere.
Set the bumper aside once you've installed all the sensors.
On the 3 door, this is the part that caused me the most headache - in order to access the reverse light feed you have to remove the ENTIRE inside panel from the boot through to the front door.
I started by removing the false boot cover, there's 4x 10mm bolts for it. Two are visible after unclipping the cover
and the other two are under covered panels in the spare wheel compartment
Note that these last two are covered and the covers flip down, they don't come away completely (unless you break them off...).
Once undone, the false lid pulls away and the cover that was unclipped before can come too - it's just held in by clips and velcro so easily pulls away.
With them out of the way the next thing is the rear plastic cover where the boot closes. This quite literally pulls away - no screws at all. It requires some force but just pull it vertically upwards and it'll come.
From this point on is where I spent a lot of time in the boot.
First, clear out the cubby at the back of the boot and remove anything you think is extraneous. I've already loosened the panel in this photo but you get the idea.
I then started at the driver's door and unclipped the plastic trim from the floor, up the vertical pillar and around the windows. Just be careful and pull firmly - the entire panel is held on by nothing but clips.
I followed the edge across the base of the window, then into the boot - along the top and down towards the back.
This gave me enough play to pull the back section away - if I'd had more nimble (perhaps Japanese...?) hands and fingers I'd have been able to carry on without removing it further but I just couldn't get my arm in there with enough room
You're looking for this
- the vertical cable cover. If you can get to it without taking the trim out, then DO IT. Otherwise, I offer my sympathies. (Side note: does anyone know what the white connector there is for? It appears to be a 12V feed...)
The trim continues to unclip along the bottom. I had to put the seat back up, unclip it, and then put the seat back down again. The rear seatbelt will also need to be pulled out next to the bottom anchor point; the plastic there splits apart by design to allow you to remove it.
A VERY firm pull removes the entire panel away from the chassis, and you can then pull it up away from the side and out of the boom to reveal the metal underneath
When I had it out, I wish I'd had some insulating material or maybe an upgraded speaker to fit as both of those are on the list... and it'll mean taking the plastics out again!
Scotchlok (or connect via another means) the positive feed to the BROWN wire in the vertical loom; and use the convenient grounding point for the negative.
In the rearmost panel you'll find two plastic grommets. Drill these (I think I used a 9mm bit). Bring over the bumper, and feed through the cables.
Pull them all the way through and you can then clip the bumper back on in the middle and loosely fix in the four retaining bolts. In the photo below you can see the loo rolls I used to support the bumper whilst I fed the cables through. Would have been handy to have an assistant but Tesco's Luxury Soft did the trick!
This will keep it in place and mean it won't accidentally fall off whilst you're routing cables. Don't worry too much about the side clips and arches as yet.
is a photo of a bit later on, but shows how I've got the cables coming into the car. I suggest some silicone sealant in the grommets to ensure you've waterproofed it - I forgot unfortunately but removing that rear plastic trim is quite easy in itself should you do the same.
I then mounted my box and connected the cables.
The majority of the excess was bundled behind the unit, however I did leave enough slack to ensure nothing would be pulled taut when the plastic trim went back on.
I've attached the beeper also here as you can see it just hanging down. The main thing now is that you want to TEST IT
. Turn on ignition, put it in reverse and check the sensors work correctly as you walk towards and away from the rear of the car. Once you've confirmed it's working correctly, think about where you want to put the beeper. Mine is next to the passenger seatbelt and was stuck onto the rearside of the plastic trim when I put it back.
In this location it's loud enough to be heard inside and outside the car - but if yours isn't so ear-splitting you might want to relocate it under the rear passenger seats.
Once you've seen how it all comes apart, reassembly is fairly straightforward. The trickest bit is relocating the plastic trim inside, but when it's in the right place it will slot in neatly without force. Before you push it back in, however - make sure you've pulled through the metal loops in the boot and relocated the passenger seatbelt! Many expletives were uttered when I realised I'd forgotten to do so and had to detach the panel again. Push it all firmly back and ensure you've not trapped the rubber anywhere along the edges. If it feels loose at all, compare it to the other side of the car. If it's still too loose then move across the panel pressing it into place. There's still a little play in the panel as I found out - I thought I hadn't attached it correctly but the other side of the car was identical. An easy one to miss are the clips at the bottom; you'll know if you have as when you lift the rear seat it will rub. It's easy enough but just take your time to make sure it's properly in place.
The other panels install in the exact reverse as removal, just be diligent to ensure you've lined up all the guide holes and plastic inserts correctly where necessary. Similarly for the bumper, as you already fitted it into place you can go ahead and reclip the side panels on (they needed a thump with my palm to locate properly), then tighten the four bolts at the back. Don't forget the retaining screws on the sides before you put the arches back - and the arches themselves just require pressing into place.
Inside the wheel arch where you removed the retaining screw is a plastic panel, if this has come away there's a plastic locating piece a little further up that can be tricky, a screwdriver came in useful to help it along. If you have this problem you'll know what I'm talking about - if not then ignore this bit!
Put back your push pins underneath the bumper (ensure you've lined up the hole for the arch also) and that's it.