This is going away from the OP's post (doesn't it always?)
The key point is that when a car is on an a-frame and conforms to all the relevant lighting and braking regulations then it is regarded as a trailer and it is perfectly legal for a UK registered combination to circulate the roads of Europe like this. Towing a trailer in Spain is perfectly legal. The car has not 'magically' become a trailer in itself but is legally regarded as one (in the UK) until there is a court case that says otherwise if that ever happens. There are 2 very obvious clues to the car being regarded as a trailer. Firstly it carries the rear numberplate of the towing vehicle - in place of its own. Secondly it has to carry two red warning triangles - these are only legally displayed on a trailer, nothing else!
The problem is that this would not apply to Spanish (and some other European countries) registered vehicles because they have specific laws that would make such a configuration illegal. The Guardia Civil are unlikely to be fully aware of (or interested in) the UK regulations on this, so will view a motorhome towing a car as illegal. So of course there will be instances of people getting stopped, possibly fined, possibly made to uncouple and there will be many more instances (IMO) of others carrying on without problems.
The only defence if stopped is to be as polite as possible and to try and explain the UK/trailer situation, the result will depend on the officer on the day. But lets face it, its not a firing squad situation! The very worst
is a fine (I'd be very surprised if it was as much as 600€) and having to continue the journey separately.
I certainly don't 'flout' the law by a-framing, but I accept that there is a very
small chance that a Spanish policeman might disagree.
I can only find the following info which is from 2007 that gives the UK official opinion on a-frame/trailer rules - Is there anything more recent?
"Note on A-Frames and Dollies, issued by the Department for Transport
When an "A" frame is attached to a vehicle (e.g. a motor car) and towed by a motor vehicle (e.g. motorhome) we believe the "A" frame and car become a single unit and as such are classified in legislation as a trailer. As a consequence the car and A-frame are required to meet the technical requirements for trailers when used on the road in Great Britain. These requirements are contained within the Road Vehicles (Construction and Use) Regulations 1986 (SI 1986/107 as amended (C&U) and the Road Vehicles Lighting Regulations 1989 (SI 1989/1796) as amended (RVLR).
Trailers having a combined axle mass not exceeding 750kg are not required to have brakes fitted. However, if the trailer (regardless of mass) is fitted with a braking system, then all brakes in that system must operate correctly. The regulations do not include design constraints on how this should be achieved but, for example, it could be met by direct linking of the trailer brakes to the brake system of the towing vehicle or by automatic inertia (overrun) operation via the towing hitch. Inertia systems can only be used for trailers with a maximum combined axle mass of 3500kg.
Regulations 15 and 16 set out the braking requirements - including minimum braking efficiencies for trailer brakes. Subject to certain age exemptions, the regulation requires the braking system to comply with the construction, fitting and performance requirements of European Community Directive 71/320/EEC along with its various amending Directives. The most recent consolidated directive is 98/12/EC. Alternatively the braking system can comply with the corresponding UNECE Regulation No.13.09.
In addition, C&U Regulation 18 requires the braking system to be maintained in good and efficient working order. If the brakes of the towing vehicle do not directly operate the trailer brakes the use of an inertia (overrun) system is acceptable. If the trailer braking system has power assistance (i.e. servo or full power) it is likely that this assistance will be required while in motion to meet the required braking efficiencies. This is because once the vacuum reservoir is depleted it is possible that the brakes will not meet the braking efficiency. To prevent the trailer being used illegally a remote vacuum pump, powered from the tow vehicle, could be installed to recharge the reservoir, alternatively a source could be made available from the tow vehicle. From 1 October 1988 the inertia braking system was required to allow the trailer to be reversed by the towing vehicle without imposing a sustained drag and such devices used for this purpose must engage and disengage automatically. This will be very difficult to achieve on an "A" frame using an inertia (overrun) device.
Other provisions from Regulation 15 and Regulation 86A of C&U require the fitting and use of a secondary coupling system in which the trailer is stopped automatically if the main coupling separates whilst the combination is in motion. Alternatively, in the case of trailers up to a maximum mass of 1500kg, the drawbar must be prevented from touching the ground and the trailer able to retain some residual steering.
Whilst being towed, trailers are subject to the relevant requirements given in RVLR, including the use of triangular red reflectors. There would be further requirements for the display of the appropriate number plate, etc.
The use of "dollies" is intended for the recovery of broken down vehicles, not for the transportation of a vehicle from "A" to "B". Under Regulation 83 of C&U a motor car is permitted to tow two trailers when one of them is a towing implement and the other is secured to and either rests on or is suspended from the implement. Therefore as a trailer if the maximum laden weight of the dolly exceeds 750 kg it must be fitted with operational brakes, additionally the brakes on the wheels of the second trailer (the towed car) must work and meet the specified requirements. Again this would be very difficult for the rear brakes of a motor car, on their own, to meet the 50% braking efficiency required for a trailer. The dolly would also be required by Regulation 22 of C&U to be fitted with suspension. Regulations 19 and 22 in C&U permit a broken down vehicle to be recovered without complying with these requirements. However, there is further legislation under the Road Traffic Act that introduces a limitation on the maximum speed that the combination can be driven; this is 40mph on motorways and 20mph on other roads.
We do not supply copies of legislation but I have included some information on various sources where they can be obtained. If you would like to purchase printed copies of Statutory Instruments these are available from TSO:
The Stationery Office Tel: 0870 600 5522
PO Box 29 Fax: 0870 600 5533
St Crispins e-mail:
Duke Street online ordering:
Norwich NR3 1GN
Alternatively you can consult "The Encyclopaedia of Road Traffic Law and Practice" published by Sweet and Maxwell. This publication is updated regularly and is available in most city reference libraries.
EU Directives can be found at:
UN-ECE Regulations can be found at:
From the above I hope it is clear that we believe the use of "A" frames to tow cars behind other vehicles is legal provided the braking and lighting requirements are met. However, while this is our understanding of the meaning of the Regulations, it is only the Courts which can reach a definitive interpretation of the law.
Primary Safety Branch
Department for Transport"
These arguments and discussions go on and on but there is rarely substantial evidence of problems. Lots of hearsay and third party conversations though.