The two wheeled dolly is a cumbersome bit of kit and takes up so much room you would be better off with a trailer.
Some dismantle and can be hung on the garage wall but again the price of these will get you a half decent trailer.
The A-frame towing option has its + and - points.
Your track car will need to be road legal to tow on the frame but saves loads of room in the garage.
I personally would invest in a decent trailer and take it from there,if you have an off on track the dolly and A-frame are useless to recover a suspension damaged car.
So in answer to your question,trailer all day long.
We have had a few debates on this on my motor club forum and the consensus was that the A frame is not a legal option unless recovering a broken down vehicle and even then is dubious due to braking requirements, as mentioned above.
Please also be aware that it is not unknown for the local traffic units to wait outside the venue to stop and check the legality of trailers and tow cars with respect to condition/towing weights insurance etc etc.
If you do get a trailer make sure it complies with all the regs particularly regarding weights and have a copy of all the relevant paperwork with you
I would suggest the AA document makes it very clear that unless broken down, you cannot tow a vehicle on an A frame because it has brakes that will not operate from the action of the towing vehicle.
If it were a light car, below 750kg then it could be towed, but again the presence of the cars braking system would make it illegal for the reason above.
It would of course be possible to disable the car, thus saying it was broken down, when leaving a venue, however it would be hard to argue when going to the venue in the morning that you are recovering it and probably cost you a good few pounds in court shouting about it.
I have also looked into this and can say that the only legal option is a trailer. There are several websites that clearly state dollys are not legal for transportation regardless of if they are braked or not. They are only legal for recovery purposes and even then I believe they are the subject of serious speed restrictions such as 40mph on motorways… I also believe that if a towed car is touching the highway it must be insured Jin its own right.
However, having said this, and believing it to be correct, I know people who use a dolly for their cars. They appear never to have been stopped by the law and don,t worry about. This appears to be mainly due to the confusion surrounding this issue where even the police are uncertain of the regulations.
Personally I wouldn’t, risk it but its not easy to tow and stay within the law. Towing with a van is also a minefield.