Vehicles constantly veering, bug or not?

Playing around with the game quickly proves, for me atleast, that predictability is a problem. Whenever I design a vehicle and ship it off to the track, it starts veering left. This causes quite a problem on tracks where precision and adjustment is key, like the relatively easy chasm level, where it would send me flying leftwards off the ramp, instead of straight away.

It seems ilogical when the vehicles are perfectly symmetric and supposedly stable. Is this a bug, or a (ill concieved) feature?