To use a "slot-it" motor pod from a junk yard, I designed a sub-chassis shown as a picture below by cutting an ABS cardboard t=2.5mm.
I designed and made a minimal chassis by using the sub-chassis and the motor pod.
The steel pressed wheels in the plastic model kit are nice looking as it looks like a real light vehicle with 360cc, I use wheels and tires from the kit for front. For rear wheels, I made insertions scraping pressed wheels from the kit and make them together with "slot-it" 312PB insertions which are scraped the center area and become like doughnuts.