$49K is a rip off, $6000 back of book on a M5 is a pure Joke. well, I think cpo kit for a dealer is around $1500-$2000 and let say they want to go below extra $1000 or $2000 your car should still worth around $51160-$52160(I think that's about max a BMW dealer will give you). Selling to public by yourself is a pain in the butt, you never know who is gonna show up. Could be a real buyer or a real Jack off or the worse..a robber. If a dealer can consign your car, probably it would be the best way to go, your car should be pretty easy for a dealer to sell on or above wholesale blue book.