718 Rear light issue and complete lack of interest from OPC - Page 1 - Boxster/Cayman - PistonHeads UK

Discovered what appears to be some micro fractures on the rear lights on my 718. The car has been parked on my drive for 12 days and not moved during that time and these fractures definitely were not there beforehand. Quick search and I discover at least two other instances of the same issue and in both cases the units had been replaced under warranty. So armed with this I contact my OPC only to be told without seeing them in person, just looking at the images here that its not covered and is caused by aggressive detergents. Here is the quote from the bulletin. OPC said: The lens is made out of polycarbonate and there is a layer of hardened coating to the outer surface of the lens, this helps to protect the lens from damage (scratches, stone chips). However, this hardened coating can be damaged by using the wrong/aggressive cleaning materials and abrasive cleaning procedures, also the same goes for headlight cleaning system fluids, this an outside influence and can not be claimed under Warranty. Please note that this bulletin applies to all lamps. I am sorry this may not be the response you were hoping for, as this has come directly from Porsche, It would not be covered. If you would like me to look into the price of the lamps, please let me know. The last sentence was the kicker. I had another look and if there is a protective coating then this is intact and the cracks are either underneath the coating or on the inside of the lens as I cant feel them. I got in touch with the OPC again to say I didn't think this was the same issue and I could bring the car in if they wanted to see it but instead they doubled down and told me to get in touch with Porsche GB directly. I haven't had to venture into an OPC for several years but when did they go from falling over themselves to help the customer to not giving a crap? Anyone else seen this issue and had a satisfactory resolution? Cheers P

That's weird! It does look a bit like stress cracking caused by a solvent (like IPA)...but, why just that edge? And...polycarbonate doesnt stress crack with solvent to my knowledge (my experience is with materials like plexiglass, pmma etc...some of those will craze and crack the moment you touch the edge with IPA). But I'm not sure that's what you're seeing here. Its deffo cracks (obviously). Could it have been caused by ice? Just casting about for ideas really.

PetrolHeadPete said: That's weird! It does look a bit like stress cracking caused by a solvent (like IPA)...but, why just that edge? And...polycarbonate doesnt stress crack with solvent to my knowledge (my experience is with materials like plexiglass, pmma etc...some of those will craze and crack the moment you touch the edge with IPA). But I'm not sure that's what you're seeing here. Its deffo cracks (obviously). Could it have been caused by ice? Just casting about for ideas really. The car has only been outside for a couple of weeks but during that time we've had some really cold nights followed by bright days and the rear of the car is in the sun all day so I did think if it could be something to do with the weather. Its also not been cleaned during that time other than a blast from the jet wash when I've been cleaning the daily. Its just a ball ache that I've now got to engage directly with the manufacturer rather than OPC.

I'd want to see a copy of the TSB. You could also try another OPC, they may look after you a little better. I take it the car is still under warranty?

Just doing some Googling and it's quite common on 718 and 992s. I think your OPC is trying to wiggle out of a warranty claim but not sure why as they cost is put to the manufacturer or extended warranty provider.

Porsche changed their warranty policy on 15th Sep 2025, including among others corrosion of any sort. Wouldn’t surprise me if this was another wriggle out. Good luck.

Spoke to Porsche UK yesterday who were somewhat surprised that I'd been asked to contact them directly without the OPC even looking at the car. They are going to arrange for my car to be looked at. I'm away for a couple of weeks so will be a while before I can report back. Boxster5 said: Porsche changed their warranty policy on 15th Sep 2025, including among others corrosion of any sort. Wouldn t surprise me if this was another wriggle out. Good luck. This is interesting. I took a 3 year warranty out in Feb 24 and haven't been sent any revised policy wording so I can only assume that this new exclusion is for all policies from Sep 25 onwards.

Given you have the previous version of the warranty, as have I, I'd be surprised if they don't replace the lights when you take your car in. As it's a known issue, I really am confused why OPCs just dont change them. Which OPC do you use?

Had a similar warranty situation on my Carrera T. Rear view mirror came unstuck from windscreen. Many examples on forums - ‘known fault, issues with bonding to lightweight windscreen, immediately fixed under warranty’. Contacted my OPC. Made me jump through hoops with photos, ‘investigation’ bookings to see them, “We may replace the mirror but you’ll have to pay £1000 for a new windscreen as only the mirror is faulty… We’ll need to inform Germany… won’t get a response for 3-4 weeks… this definitely won’t be covered by the warranty” etc, etc. Weeks passed “We’re still waiting for authorisation from Porsche”. They finally phoned to say Porsche had agreed as a “goodwill gesture”. When I took it in for the repair, service manger couldn’t believe the hassle I’d had. Said it was never going to be declined by Porsche as they’d had loads with the same issue!

My lens cracked in several places on the nearside rear light. It definitely hasn’t hit anything so I’m guessing it’s temperature related. I’m going to have a go with a lens from China ( looks right ) I know they are plastic welded but it’s either that or another unit - mines out of warranty..

Fairly clear that is delaminating either through a manufacturing fault or design issue. It's well known on headlight units. If you have no luck with Porsche there are now services which replace the lens. Most seem to advertise headlights, but it must be worth a call to find out if they do tail lights and how much? This is just one such company. https://rennlens.com/lens-replacement-3/

Heard from Porsche UK/OPC whilst away and they are washing their hands with the issue and saying its outside influence. It would appear that the best way to get rid of this unsightly issue is to have the lights sanded with wet/dry to remove the UV coating and then polished and re-coated. I'll make some enquires and report back.

I wonder what percentage the bean counters at Porsche apply to the calculation for damage to reputation as a result of refuting claims like this? This, along with other things, is going to bite them hard, but I’m sure that the people that are responsible for ‘making savings’ now will be absolutely fine.

Final response from Porsche UK. Porsche UK said: Dear I hope you are well. I appreciate your patience while I have reviewed the details of your case, regarding the recent inspection of the rear lights on your 718 Cayman GTS 4.0 at Porsche Centre Bolton. Porsche Centre Bolton visually inspected your vehicle in March 2026 and identified that the internal cracking visible within the rear lights is consistent with exposure to harsh cleaning chemicals during washing. Based on this assessment, the concern has been classified as external influence rather than a manufacturing defect. They discussed their findings with our internal Warranty Team at the time, who confirmed they agreed with their assessment. We have also reviewed your vehicle’s Porsche Approved Warranty (PAW) cover. While your vehicle does benefit from an active warranty, this type of concern is unfortunately not covered as it is considered a cosmetic issue and does not impact the functionality or performance of the lighting units. We do appreciate that this is not the outcome you may have been hoping for. As a next step, we would be happy to review further to determine whether any goodwill assistance towards the cost of repair may be available. Should you wish to proceed on this basis, we will liaise with Porsche Centre Bolton and obtain the relevant information and costs. Alternatively, if you are unsatisfied with the outcome of this review, you may wish to seek advice outside of Porsche on your available options and customer rights. Porsche subscribes to The Motor Ombudsman who are an independent service dedicated to the Motor Industry. They have legally trained representatives who provide free and impartial advice. Should you instruct them to investigate your concerns, and they feel Porsche are acting against you as a customer, they will make recommendations to us on how to reach a resolution and arbitrate on your behalf if required. The Motor Ombudsman can be contacted on 0345 241 3008 or via their website - www.themotorombudsman.org

I'd speak to the ombudsman