I was tought by my dad and I tought my children not to touch anyone's car, motorcycle or what-ever at any time for any reason-ever, not even mine. If you teach them that right off then you should not have an issue of your child getting burned, cut, ECT.

I guess Roger, as long as your grandchildren know not to touch unless mom, dad or grand parents say it is ok, then that works for you and yours.
Good looking young grandson's you have there. Even if we can only see one of them

Take care,