you might want to check out ELO Touchscreens
under "products" they have AccuTouch touchscreen components. im not sure what size you would need, but have a look around. there a quite a few touchscreen companies that sell components, but since im at work, im brain-dead and cant think of any other ones.
just a little trivia side note, the impee3 car website is the site that really got me interested in this whole car mp3 player culture. just a little ego building praise for you...assuming that is your page in your sig!
Single Member of the "1000 Post and No MP3 Car" Club
PROJECT ON INDEFINATE HOLD... BOUGHT A HOUSE
2000 Cavalier Z24 [###-------] Only 30% Done ... Still
ELO doesn't sell touchscreen controllers that small. I used to do a lot of business with them at my last job. I found a Kenwood widescreen touchscreen ($1300), so the controller must exist somewhere. I'll keep looking.
Wow, that's cool that you like my site. Thanks! (Yep, it's my site.) For me, it was ryanspc.com that got me inspired.
I have a new car now and I want to do it all over again. I guess I'll never learn.