A - frames.no no
I answered this question quite a while back,while towing a Suzuki GV ragtop with a brand new 2 tonne A- frame with a long wheel base Nissan Terrano,nearly 2000 miles !!
It is not legal in Germany and Austria as i was stopped several times (lol) managing to be very lucky every time,me and the Mrs (luckily) had to unhitch and drive the two seperate !!!!and this is how stupid it is,they made us unhitch and drive Suzuki seperate without asking for road legal documents !!!
The reason for towing,cheaper (1 lot of fuel) faster,as i can tow at 65mph and the vehicle can ,as my Mrs can't,and also she panics more as not experienced.
Not sure of other European countries but what i gathered from police,they are not recognised there,some never seen one,and were bouncing up and down on unit when hitched up,him being a Bavarian sausage eater of 6'6" and 25 stone or more (git)apparantly there is an on the spot large fine they can give out,or even conferscation,they can and will weigh you too,as they did one time with me ??luckily again within limits.
I dont know if theres a different ruling with the independant BRAKED A-frames that use the towed vehicles brakes???Otherwise its a trailor i'm afraid,why i dont know,as the car/vehicle is a trailor when fixed ????
One thing i found when using the new A-frame i had....it worked loose,and become very wavey going down the long hill into Dover port....eeeegh,i re-hitched and solved the problem by using extra bolts,washers and nuts,long enough to pass through the looped chain,thus clamping them together at contact,and both sides of frame/ends of car.