Re: My son's first 'car'...
Too bad it's an inflatible, with a RIB you can get some nice neon green, purple, red or what ever color he likes and pimp that boat up by painting the glass.
You/he can still do that to the transom and engine - make it special and highly visible at the same time.
I would not go so far as to add some chrome work, but YMMV.
The exterior paints the make for hypalon and PVC boats is also a good deal, easy to apply and visually well worth the effort.
Don't worry about the nay-sayers - your kids probably have more time and experience driving dinghy's that most sailors do. I'm lucky to get a donzen hours of dinghy driving in during a season.
Lessons learned are opportunities earned.