No used TDI's that's for sure and the TDI WILL generate a price premium and they no doubt have waiting lists for them. That's what happens when you build a superior product. Audi made over 800 Million USD first hald of 2009 because they have product people want to buy.
I own my Audi free and clear and it will retail for around $10,000 if I sold it today in the middle of a recession and it is 9 years old.
Plus I wouldn't buy a thumb screw from General Motors, They are the US Airways of car companies. Constatny striving to be "Good Enough" I'm guessing a fully equiped Tahoe isn't a whole lot cheaper then the far far superior Audi, plus you get the satisfaction of flipping Barrack Obama and his Socilist dim bulbs the finger. Sounds like a win win to me