We have a three year old Autotrail (owned from new) which has developed 2 cracks in the roof. Autotrail are saying that it is not covered by warranty as GRP defects are only covered for 12 months, albeit they cover water ingress for 10 years and the crack is allowing water in through the seams. The vehicle has not been hit by anything so this appears to be some sort of stress crack or original fault. We have had all sorts of trouble with this van since day one but I would like to know if anyone else has suffered from random roof damage / cracks. This fault seems to make the motorhome not fit for purpose. Any thoughts or advice please.