Just a bit more info re this (we’re currently touring France for 3 weeks in the 718).
I called into the dealer who sent me straight to their approved bodyshop.
The assistant manager looked and tried to take photos to send to Porsche GB. It’s not easy with the wheels on.
I’d already taken photos when I took the arch liners off so agreed to send them to him to be sent as part of his “report”.
He did say to fight it as they were notorious for rejecting claims.
The Bodyshop came back saying that Porsche had rejected the claim and to speak initially with the dealer who would try to argue my case but in the end, if that was unsuccessful I would need to contact them myself.
Net result is they’ve rejected the claim within hours it seems and “would not reverse their decision” which to me is rather an arrogant way of dealing with the matter.
Confession time first, I took the car out of the main dealer network after the 4 year service so it does not have the 6 & 8 year bodywork stamps. It has since been serviced regularly at well known independents in my area.
Having said that, I would doubt that they would have picked the corrosion up as it only became obvious after removing the arch liners. I’m pretty sure they don’t remove them as part of an inspection?
Surely stone chips to the underside are impossible to stop and with regard to the front arches, the liners prevent that! There is a tiny gap between the liner and the wheel arch so I assume that has let moisture in and has caused the corrosion to start which has travelled up around an inch or so from the lip.
There is some minor paint bubbling on the wheel arch lip (nowhere else).
The Motor Ombudsman definition of corrosion or anti perforation is starting from the inside out - is that not what this is? (I have the exact wording somewhere else but not whilst we’re on holiday)
The rear arches are a poor design with effectively a U shaped channel where debris can sit and I think that is where the corrosion has started there. It appears to be within the U shaped channel and there is some paint bubbling on the lower and inner wheel arch lip.
I would say the corrosion may be at the early stage so may be recoverable.
Speaking with the bodyshop, they said that in order to put a warranty on the work as Porsche insists they would be looking to replace both front & rear wings - total cost circa £11,000


- not sure if that was the exact amount or if there was VAT on top as I fell off my chair at that point!
When we return from holiday, I will contact Porsche GB by phone but failure with that approach I’m sorely tempted to consult with the Motor Ombudsman.