Having read this thread, it does seem the CRA would have been the route to take regards the cracked panels. The CRA takes the manufacturers opinion out of the equation, and the liability falls on the seller.
But it does raise another important issue. The CRA requires that goods are of a merchantable quality and sufficiently durable. Products should be designed and manufactured with that in mind, becasue sellers (dealers) are not going to be impressed if manufacturers continually supply goods then wash their hands of problems when the sellers are still exposed to the liability under the CRA.
This is another example of how the caravan manufacturers continue to ignore the impact of their poor design or choice of materials on their end users, by hiding behind their dealers and the fact they do not make the retail sale.
I do wish there was route for end-users to have a readily accessible route to bring faulty design or manufacturing action directly against manufacturers beyond the limitations of the manufacturers guarantee. As it stands the customer can only bring action against their co-contractees., and hope that enough actions make the sellers be more forceful with their suppliers about quality of products.