GURPS Vehicles is the definition of fiddly unless it's changed drastically since either of the editions from the GURPS3 era I have. Did they do a new one for the game's fourth edition?

GURPS4's Spaceships is a good suggestion and was the first system I considered, but I found myself making too many adjustments and corrections. I got to about ten pages of handwritten notes before I ventured into seeking alternatives.