What do you guys think are some of the rarest cars in Gran Turismo 5?

I have had an extremely difficult time finding the Mercedes-Benz CLK-GTR. Not the DTM, the CLK-GTR. It’s the mid-engined one.

If anybody has one, and would be willing to make a trade, my PSN ID is hogger129.

But what are some of the toughest cars to find that you guys have been looking for? I may be able to make a deal with you.