Ford has really jumped on the "cash-for-clunkers" news. Before Obama's ink was dry, Ford put up a web site (the impossible to type www.letfordrecycleyourride.com) which lets you input you car to check if it is eligible. Then the page shows you a list of Ford vehicles which would qualify for the voucher. Ford puts a happy green spin on the whole thing by offering to "recycle" your old car, which is much nicer than "scrap". It's very slick.
It surprises me that none of the other major car makers did the same thing. I checked the home pages of Toyota, Honda, Nissan, Chrysler, GM, Kia, BMW, VW, Mercedes, and Subaru. None of them had any CARS information.
The only other major automaker which has a CARS information site is Hyundai, here. Hyundai's site is not as slick as Ford's but it does give a list of Hyundai vehicles which are eligible for the government voucher.