Hi,

having owned a motorhome that had the same issue the problems caused can go somewhat deeper than what appears to be the issue on the surface. On first look it usually appears to be fibreglass bumper/panel cracked that needs replacing, but these things have flimsy plywood insulated sandwich floors that overhang the rear sitting on a solid metal chassis behind them, Any knock can break these up and crack them which would allow water ingress and rot to occur. There is also the possibility that the sides that attach to the floor can get distorted, by their very nature they are lightweight and their limited strength comes from the whole, disrupt that and you have a major problem..

Replacing a broken floor or union between the sides involves removal of a lot of internal cupboards and fitting and that is where the labour costs mount up. On first sight these vans look substantial but the reality is they are flimsy,and a sideways push on an angle on the rear can cause major issues and goes a long way to explain why the insurance exclusion on the bumper. On hire vans the reality is unfamiliar drivers with the length of the vehicle will often hit things on the angle reversing causing the issue, and overwhelmingly the bulk of damage on returning vehicles will be from bumper hits.

Whilst l have every sympathy with your predicament your hirer may not be ripping you off, did you actually check underneath behind the bumper for yourself, check the inside floor behind the internal lockers, or notice any gaps appearing from cupboards and overhead lockers indicating a twist in the body before handing the vehicle back. Have you asked for a breakdown of the damage aside from a replacement outer fibreglass panel, which are usually single skin with no substance, only the supporting metal brackets which will be attached to the floor and any buckling of these will cause floor damage.

David