But but but .... How do you properly tie down the kid, w/o the appropriate 5 point seatbelt?

Thanks for the link, I'll have to file that away. We just had an instep trailer given to us; other than needing a special tube it seems just fine. I think the people who gave it to us got it for free, off of freecycle or craigslist.

[One flat tire, I sorta patched it--slow leak--but this is a low end instep model with plastic wheels. The tube stem will not take a proper pump; it was replaced at some point with a standard tube. The other wheel has a special tube that has a metal valve stem that angles the tube outwards.]