You might want to try Copart.
http://www.copart.com They used to buy lots full of flood cars, train wrecks, etc. You might also want to call your insurance company and find out what they do with the flood cars they buy.
Key to your getting a great deal is finding a way to purchase the car at auction before the pick-a-part yards get them. Once they've got it -- they're going to mark the price way up. Good luck.