I do find it alarming that caravan manufacturers make these warrantee offers, band tie it up with such strict and limited access. Why should a change of ownership suddenly make a lifetime warranted product more likely to fail?. Cynically I suspect Buckman is correct.
If they genuinely had faith their product would remain waterproof for life they would not need to make a song and dance about it. They'd only need to sit back and watch their warrant costs reduce as claims deminish.
But Joe and Josephine Public are being hoodwinked again, you can have a lifetime warranty but you must pay for it, by agreeing to have it checked at your expense. As we haven't seen all the details yet, but essentially for a manufacturer to be prepared to make such a dramatic offer which implies they have unfailing confidence in their design, materials and workmanship strongly suggests it's not even a serviceable item. There is no regular maintenance so it will ether be good or if it does leak it's automatically faulty goods, so why the need to inspect?
You can buy cutlery with a lifetime warranty, do you have to have it serviced and inspected?