Despite the contraindications a buddy of mine used to do this. He found
a way to get a car battery in those lil cars and they worked great !
His grandkids rode around the campgrounds three at a time and went over
bumps etc. that would normally stop these things.
Generally they seemed to have 12 guage wiring, so if you use that or
heavier and keep the wiring concealed the danger isn't that great. If
you look at the switches that control the thing they will be what burns
up, not the wires.
Things happen, but the cars we had didn't have doors or seatbelts so
even if it started smoking they could just hop off the thing.
The attitude was : You only live once. The kids had a blast, and yes
things did happen but nobody got hurt. After awhile of course switches
and motors and gearboxes needed to be changed, they broke of course.
If you do this, keep an eye on them, they may well be able to run each
other over etc., but even if they ride these things in their "stock"
form they should be supervised.
Always keep in mind the danger of fire, and if you live in dry country
be especially careful. If you start a forest fire you not only go to
jail, it's wrong. Do keep an eye on things.
As far as getting the parts, my buddy actually picked the garbage, as
did his friends. I normally don't, but for the kids I did pick one up
when I saw it. Almost always the problem was bad batteries. I know of
no other way to get the other parts, such as the wheel motors ets. We
just put the good parts in the best cars and got rid of the rest. Foot
pedals and reverse switches did not last long.
JURB