Phil - diffuser is (basically) normally somthing which smooths the air flow, and on race cars is often used to help add some downforce, normally over the driving wheels.
Or sometimes to help add directional stability.
But basically all to do with 'diffusing' the swirling air caused by the car.
I'm pretty sure that would be what Honda would call the rather nice bit on Caz's car, picture 1
Caz - re chipping - guessing you've seen the various tuning threads in the Engine section
A custom map (one designed and tested on your particular car) will generally be better than a generic map (all things being equal and the 2 tuning companies having the same level of skill).
Never heard of Upsolute - but...
they only seem to have 2 UK distributors. One in Derby, and one not far up the road from me.
United Kingdom UPSOLUTE UK
CCC Technology
Simon Coe
Dronfield - Derbyshire
England phone (+44)(0)1246 411021 fax (+44)(0)7957 240822 e-mail contact@ccctech.co.uk homepage www.ccctech.co.uk United Kingdom UPSOLUTE South Wales
Digital Tuning Solutions (DTS)
23 Felindre Road, Pencoed
Brigend, CF35 5PB phone (+44)(0)7957 309640 fax - e-mail DTS@upsolute.com homepage www.upsolute.com
The South Wales one does not have it's own website
The Derby one does have it's own website - but the last testimonial on there was from 2003...
According to the Upsolute main website, they chip the Accord 2.2 - but no mention of the Civic.
They
might be fantastic - but I would dig a bit more before parting with any money if I were you
And finally - if you are concerned about that sort of thing, make sure that you get
in writing that your dealer will still be happy to service your engine
under warranty if you take up their suggestion of having it chipped
On a rather more upbeat note -
love the body kit!