I just realized that I'm going to need to make railcars for GURPS Metro. I think I can just use jeeps out of high tech for surface transportation at least. There MIGHT be rules for a hand cranked railcar given that I can modify if I'm really really lucky.
Building things in GURPS vehicles is so bad that it requires the use of differential equations at times.
I really don't want to use GURPS Vehicles, but I want to have actual stats for things. I don't really want to have to build another book just to get usable rules