An A frame is for recovering a broken down vehicle to a place of storage or repair. Once there the vehicle cannot be moved again on an A frame. A frames are not trailers as they cannot meet the Construction & Use Regs that apply to trailers.
The legislation is widely abused with few prosecutions and those usually occur within a few miles of car auctions selling accident damaged vehicles.
Recovering vehicles by A frame on motorways requires the unit to leave at the first exit.
I thought that is a towing dolly with the little wheels on that you lift the front wheels onto and strap it down.
I meant a proper A frame that bolts to attachment points on the car and having a connection to the car's braking system such that the towed vehicle's brakes work when the towing vehicle brakes, and come on if the coupling detaches from the towing vehicle. (So they
do meet C&U for trailers if they have the correct lights & reflectors)
You see them attached to Smartcars behind motorhomes.
Obviously, the trouble of sourcing and fitting a proper A frame makes it a non-starter for the OP's proposed use even if the towed vehicle didn't need MOT, insurance or tax.
