28 years ago I bolted a skeleton to his motorcycle then bolted them both to the side of my car (See
www.hauntedravensgrin.com)
At least back then, in Illinois, you could have strange things attached to the passenger side of your car as long as they were not protruding more than 9 inches?
I sawed the old dirt bike in half, length-wise which taught me how strong steel dirt bike frames can be!
I made the skeleton myself from pvc, sheet metal, styrofoam and Bondo, not something I would recommend it was very time consuming , but it did fool medical people into asking me "Where did you get the real skeleton?"
Having my Ex pull out infront of a Volvo going 55MPH and get "T-Boned" did help much in creating the required space for all of this to be able to happen. (I don't recommend calling her and asking her to drive your car either.)
The 79 Thunder Bird was declared "Totaled" but the insurance crooks didn't want to part with enough money, so I kept the car, fixed it enough and hit the road with it, terrifying a great number of people along the road and driving in the road.
I was NEVER pulled over by any Policeman anywhere and I did drive this car to Chicago and as far south as New Orleans. A former Co. Sherriff lied to one of his jailbirds and said he had pulled me over countless times and issued me numerous tickets-Nope, never even once, anywhere, but laws by you may vary.
I eventually removed the bike and it's Boney rider after many years of drunks punching him, pulling on him, and attempting to steal his fiberglass WW2 German helmet from his head, because it was not made to actually handle that kind of vandalistic abuse and I was concerned that they may have weakened some of it and parts might begin a trail down the road behind me.
Everybody wanted to steal his helmet, so I took ribbed tape , pushed numerous carpet tacks through it , stuck it under the edge of the helmet and suddenly nobody was taking the time to pull on it anymore?
I was waiting for the time I would walk out of my house to find some drunk messing with this car. I would dream about simply smacking that person flat across their shoulder blades with a baseball bat and say:"Sorry! YOU were Drunk!" (instead of them saying ,"Sorry I was drunk." As they would suddenly quit pulling or kicking my guy as I appeared .
My test once something like this went on a car was to get a lonely piece of road and watch everything closely as you exceed the legal posted limits for just a while, try a bumpy road too, check bolts and washers often and use locking nuts when possible. Welded steel is good too.