I knocked about on a FB self build camper van group for a while, unfortunately I think a few of those built over lockdown will go up in flames this year plus the possibility of a log burner going through the windscreen in a emergency brake/impact scenario.
Assuming you mean "A" frame towing... Some Smart cars are suitable for "A" some aren't. Depends on gearbox. If anyone is thinking of doing this I suggest a little research first. If "Hospital trolley" means a dolly with 2 car wheels on dolly and 2 on the road. These are illegal except for recovery purposes.
I would also point out that the car in this case was not a Smart car.
This has just reminded me of travelling back through France last Oct. A site we stayed on had a MH with a small car. (wished I took a pic now) When they where about to leave site, the guy put the car onto a purpose made two wheel trailer. He winched the car on and it sits in 4 depressions for the wheels. Perfect fit with no trailer base protruding. Just ratchet straps to keep in place.