I went thru the whole 20 week thing back in September 2006. I was being told by my local dealer mid-November, then suddenly everything was pushed for
NHB to end of January, a jump of 2 1/2 months overnight.
Hunting round I found some places talking early/mid December & actually committed via Autoebid to a dealer in Norwich who claimed mid December & gave me the best price.
Although timings slid out to indeed be start of February (via end of March too!!), I can accept that this was the production line's fault & not the dealer's.
All Honda Civics are going to come from the same factory so I can't really see, in hindsight, how any dealer can offer shorter lead times, UNLESS they already have your chosen spec on order.
Ask at any dealer & they should be able to tell you if your chosen spec is in the pipeline for another dealer, either for their forecourt, specific customer or as a demo. You can then try to get them to do something to get that car for you.
My chosen dealer made up for the mid-December to start of February delivery lag by sending me a Type S from mid December until delivery of my car, which I thought was a pretty fine thing to do & more than made up for the delay. It gave me a chance to get used to the basic gadgets before I got my satnav &
HFT etc & meant the 1st 1500 miles didn't go on my car!
I did find a Type S with most of my chosen extras 400 miles away whilst waiting for my EX, & was tempted to switch to that, but having got my EX I am so glad I didn't go that way.