[bystander]

Originally Posted by JohnM

Nope.
Check out the US DOT's standards for low speed vehicles.

Thanks for the link. By "Nope", I suppose you mean the S5.b.8. - windshield, and S5.b.10. - seatbelt requirements. It looks like the rest (lights, signals, reflectors, mirrors, parking brake) could be tacked on. Perhaps S5.b.8 could be circumvented by wearing a helmet that includes a faceshield. Not sure why S5.b.10 is apt for a vehicle with a saddle type seat. Motorcycles, mopeds, bicycles and equestrians do not face this restriction.