we have a similar kind of system in canada......get a discount off a new car or donate it to charity and get a tax reciept. quite a few seem to be taking advantage of it judging by how many of them i pick up. we get them and cannot sell them at all, we arent even suppose to sell the engines out of them. they are now talking about giving a discount coupon for the purchase of a bicycle for trading in an old clunker.
this is our program
http://www.retireyourride.ca/home.aspx