I helped out my son who had do a project for school where a vehicle ran back and forward if it hit a wall. We took the (incredible) model from ChaosCoreTech and mirrored the front.
Since we're not that good at painting we cut the model in separate parts so they could be printed in different colors without needing any painting. Everything was printed in Polymax PolyPlus and the tyres in PolyFlex.
It's all still a bit rough with switches and potentiometer hanging out but it runs fine for now :