Thanks for trying :)
I've actually spent a lot of time on improving the player code since the game jam ended (it's not possible to lean over things and to stand on moving vehicles), but it still keeps stepping on things when it shouldn't and goes flying when holding on to the object you are standing on, it's a surprisingly tricky problem.
Could you potentially ignore the player body while building (just allow grabbing and interaction of parts)? You could have a visual indicator and not allow spawning of a new piece by testing if there's a collision. Perhaps there could be a toggle for a 'drive mode' or contact mode that allows you to continue building while you're on top of a vehicle/structure.
You've probably already done something like this but just figured I'd throw out some ideas. Will be checking back for the update!
