Last night I was backing up my E53 with a couple of dirt bikes in a trailer up a slope and when I finished I saw smoke come out of the engine with a plastic burning type odor. There were no warning lights on the dash so I thought it was all ok. This morning, starting up the car I noticed I couldn't put it into any gear, like the gearshift was blocked or something. Long story short, I couldn't drive out of my driveway this morning because I think I blew the clutch with my little backup stunt last night! Any recommendations on the most cost effective way for repairs in this case? Thank you!