I've been trying to get this one working
http://www.fantasticcontraption.com/?designId=11752941 (another version with a small change
http://www.fantasticcontraption.com/?designId=11752938 )
I started working on it quite a while ago. The idea is to make little car flip in the correct way when it falls off the lower platform, if it manages to lock on the bridge with the

on bottom it should drive all the way back up. I never quite got it working, as you will see in one of the designs there is a problem with the chain down to the brigde, also there is a problem that occured later with the

getting stuck under the bridge while the car wanted to drive up.
I left an empty spot in the build area for something to push the big ball out of the way(But I never got that far).
Anyway, I'm getting rather bored of it(mainly because tweeking this thing is hell, small changes=big differences) so I'm just gonna leave it here for anyone that want to give it a shot.
So

to whomever completes it!
(Disclaimer: In the event of someone completing this design you will not be awarded

, as DoktorQ INC is a stricly non-profit buisness. For more information send a message in a bottle to Kola Peninsula in north-west Russia.)