I took the awesome bus from ChaosCoreTech, lighted it and put the interior from CPT_Spekkie in it. The files are all sized to 85%, it was easier for me to print.
I put two AAA rechargeable batteries inside. The front lights are lighted with 3mm LED's. The gear shifter is the switch for the light.
I printed the body with supports, everything else without. The body was printed in 0.2mm, I'm so impatient :-). The small parts were printed in 0.1mm, everything else in 0.15mm.