[RKDinOKC]

If buying at an auction.

Study the car, the auction itself is not to provide information on the car, only to accept bids to sell it.
The auction house should provide a guide for the cars being sold with lots of info.
The cars are on display to inspect if interested.
Fix a price you are willing to give for the car.
Remember the auction itself gets paid a fee over the auction price of the car.
Do not go over the price you established to pay before the actual auction.

If it doesn't meet the reserve and is still under what you were willing to pay, go talk to them. It ain't over just because it didn't sell while the auctioneer was hocking it.