Okay, got the thing working, but i had to make it a little big though as you have to extrude walls which are not angled so ship won't fall off the track. Right now i'm going on a short walk but when I'll be back I'll write a short script which will respawn your ship in last known position which was on track if your ship is not where it's supposed to be. Then I'll send you demo so you can check your track. (quite interesting i must say )