When I was a teenager I towed a heavy moped trailer made of steel and wood behind my bike to haul a lawnmower to my parents off site property. The bike was a 3 speed with coaster brake. No stopping it going downhill. lol... No I would not recommend a trailer for cars which would be even heavier.
A used kiddy trailer with the seats ripped out is light and cheap. For heavy loads the trailer needs to have brakes and maybe even electrical drive.
These look cool:
https://www.carlacargo.de/en/
International Cargo Bike Festival: Low Impact City Logistics; Introducing the 'Net-Neutral' e-Trailer
Or the "18 Wheeler" like recumbent: