An alternate that worked for me was AutoTrader. You need to shop very carefully but there are a few really low mile quality cars out there. Also a lot of modded and high mile examples - not interested. I specifically wanted a one-owner, low miles 2013 model, black or red M6 and waited/watched for several months. I did a lot of research and ended up buying a black one with 6k miles on it. I had multiple calls with the owner to get the feel of how he treated the car, cross-checked everything with GM service records, stalked the owner on FB to see if he posted any burn-out videos, created a good relationship with the service manager of a local dealer, had the car taken in for a full inspection, alignment check, and oil/filter change (my pay) and basically had a "walk-away" agreement with the owner if the dealer found any issues. I did all of this over 60 days, remotely on a car over 1,000 miles away. Never saw it until I bought it. Ended up with a perfectly smooth transaction: took some cash and a personal LOC for balance, got cashier's check for transaction amount, flew in, got a rental car, did a visual on the car, went to the bank to handle the transaction, got title, got the car keys, returned the rental, took a cab back to the car, stopped by to thank the service manager with a gift card and had a really nice trip home, getting to know the car. Got home, got car titled and did a title loan (very low rate, 72 mo. at my credit union) and paid off the LOC. 3 months, 2k miles (plus rotofab, race ramps, gorilla lugs, ZL1 valve stem caps

, black taillight bezels and pulled F8 fuse) later, all is still awesome.
My choice #2 car was a beautiful red one in NC with 2,400 miles. I spent many hours on email and phone with that guy but ended up going with the black one. That car is still available and worth a look if you like the 2013. This whole process can be risky but with proper planning and "walk-away" rights, it can work. Got my wife a nice 2010 Mustang convertible last year that way too - again, over 1,ooo miles away. I am very OK getting a depreciated, near-new car this way but it does take a lot of work and a bit of good luck.