Looks like a fun car to advance into the full size stuff ! I'd like to make one safety related suggestion though. That lap belt is waaaaay too long. It will stretch a good 4 inches in a hard frontal impact. You want your son to be strapped in TIGHT, so I've included the below pics showing how i set up MY race cars and any I build for others. Those lap and shoulder belts need to be as short as feasibly possible. You also want to install some sort of protection on ANY metal edging that the webbing will pass through or by to prevent chaffing/cutting.
Your #1 top most PRIORITY is the safety of your driver in ANY type of incident. GOOD to EXCELLENT safety gear from his nose to his toes !
