I agree with Jerry.
"There are no finger prints under water."
Towed many a bike by just having the rider hang onto either the door handle or grip the top of the door with the window down. Just gotta go slow and leave the bike/rider plenty of room on the right side of the road. Usually giving a quick tow to get a bike with a dead battery started.
Damn I hope nobody waves at him. He'll lose it for sure.
We always used a rope and just held on to it. Let go any time needed. Always slow and cautious. Would be a drag to tear up a bike or get hurt cause you're cheap or poor.
Wouldn't want to fall and break your arm and not be able to wave for the rest of the season.