Hello Dan & Paula.
I'm sorry you have stone damage to the front of your caravan, it seems that Bailey Alutec caravans are susceptible to this kind of damage.
It is a fact tow vehicles will throw stones up, and the severity will be affected by the road surface and the way the vehicle is driven.
It is also a fact that any caravan surface is likely to be damaged if hit by a stone thrown at it. Different surface materials and their substrates will respond differently, and some may be damaged more than others. The manufacturer chooses the materials to use through their design processes. One would hope that the design considered resistance to stone impact damage.
I fully understand your desire to return your caravan to its original condition free of charge. You may try asking the manufacture for a repair under goodwill, especially if it seems to be a common problem.
If you are adamant on pursuing and FOC repair you will need to consider legal services to argue your case. Whilst I believe my advice below is correct, you should seek professional legal advice before proceeding on any points. Its only fair at this stage for me to express my belief that your chances of a legal success are very low.
To obtain a free of charge repair for the stone damage to the caravan you have two possible routes using the tools you have been provided with. The Sale of Goods Act, and your Manufactures Guarantee. These two tools are both contracts but very different, where as SoGA is a statutory requirement, the Manufactures Guarantee is not a legal requirement, and can be very restrictive as to its use and application.
Unless the Manufacturers guarantee includes some provision for the repair of stone chip damaged in its terms and conditions, then I seriously doubt you can use that route to obtain an FOC repair.
SoGA on the other hand under some circumstances might provide a solution - but I am not confident of success. It is designed to provide a fair outcome for both buyer and seller, - so unreasonable expectations are not likely to be met.
The act makes the seller (Not the manufacture)liable for any faults in the goods. The act requires that goods sold are of merchantable quality and be fit for purpose. This implies that the goods must be free from design, material & Workmanship defects (these criteria are not mutually dependant) and fit for purpose at the point of sale (POS) and for a reasonable length of time following the POS.
From a design perspective, you would have to show that stone impact from a tow vehicle was not adequately considered in its design process.
Or that the materials specified were not sufficient to provide reasonable resistance to stone impact.
Or that the materials were not to specification or that faulty workmanship had been used in the construction of the caravan.
If the manufacture has issued any modifications or accessories specifically related to repair or prevention of stone damage, this may give weight to your position.
If your case relies of the evidence of your own caravan, then you would have to be able to show that your caravan has not been abused or exposed to unreasonable or extreme conditions.
Citing the lack of stone damage to other makes and types of caravan may help to give sufficient weight to call into question either the inadequacy of the design or materials used.
I think you will see that the burden to show the manufacture is wrong in either design or manufacture will be highly problematical, and to do so may involve considerable expense, of which there is no guarantee of successful recovery.
On balance I believe approaching the manufacture for some goodwill gesture towards repairs would be about the best you could realistically achieve.