Stone chips on your rear arches? There’s a fix for that

If you own a Porsche, you’ll know the spot. Just ahead of the rear wheels, where the bodywork flares out, is right in the firing line for everything your front tyres kick up. Grit, gravel, salt from gritted roads. Give it a few thousand miles and the paint there starts to look tired.

That’s exactly the problem MagnaFin stone guards are designed to tackle, and the range is now available at Design911. There are two types to choose from: magnetic MagnaFins and WrapFin removable vinyl stone guards. Below, we’ll walk through how each one works, which suits your car, and how to look after them.

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Meet MagnaFin

MagnaFin is run by Shane Altman and makes stone guards specifically for Porsche rear arches. Instead of being a generic strip of film, each guard is cut to fit a particular model, from the 911 G-Series and 944 right up to the 991 and 992.

The range comes in two types:

• MagnaFin magnetic stone guards stick to steel body panels using a high-energy magnet. You can take them on and off whenever you like.
• WrapFin removable vinyl stone guards use an adhesive backing instead, so they work on panels a magnet won’t stick to.

Both do the same job. The difference is how they attach, and which one makes sense depends on your car.

MagnaFin magnetic stone guards

The magnetic version is the one people tend to get excited about, and it’s easy to see why. You put them on before a road trip, track day or car show, then take them off when you get home. No glue, no tools.

MagnaFin says they can be used every day, but they’re mainly designed for when you need them most. A few things to keep in mind:

• Take them off to wash the car. Clean them with whatever you use on the car, front and back, and only refit once both are completely dry. MagnaFin warns that moisture left underneath in direct sunlight can cause hazing in the finish.
• Give them a wipe at least once a month. Even if you leave them on, take them off occasionally and wipe the back of the guard and the panel underneath.
• Smooth them flat when refitting. Run a microfibre cloth over the whole surface to push out any air pockets before you drive.
• Store them flat and separately. Keep them in the bag they came in. Don’t stack them, because the magnets pull against each other and can develop waves. If that happens, MagnaFin’s tip is to leave them flat on a metal surface, like a fridge or tumble dryer, for a few hours.

WrapFin removable vinyl stone guards

WrapFins started life as a solution for the 718 and 992. Both use aluminium body panels around the rear arches, so a magnet simply won’t stick. MagnaFin can now make WrapFins for any model that has a MagnaFin fitment.

Once they’re on, WrapFins need no maintenance and can stay on as long as you like. They’re designed to work like PPF, as a sacrificial layer that takes the hits so your paint doesn’t.

The clever part is getting them off. Unlike traditional vinyl stone guards or graphics, MagnaFin says WrapFins peel off cleanly in one piece, without heat or a scraper. They’re meant to be single use, but if you remove them carefully and store them on the wax paper they come with, you may be able to reuse them.

Choosing a finish

The two most popular finishes are Deep Black and Carbon Fiber.

• Deep Black has an OEM-style texture, so it looks like it could have come from the factory. It’s a good choice if you want protection without changing the look of the car.
• Carbon Fiber suits cars that already have carbon details, or anyone after a sportier look. 

Got old stone guards, PPF or a ceramic coating?

Good news: in most cases you don’t need to remove anything first.

Yellowed or cracked clear stone guards. If your car has factory or aftermarket clear stone guards (the PPF type), both MagnaFins and WrapFins can go straight over the top. This is one of the biggest benefits of the range, especially on older cars. Peeling off old, brittle stone guards can sometimes take the paint with it, so covering them is often the safer option.

The exception: G-Series and 930 Turbo shark fins. Many 911 G-Series and 930 Turbos came with thick, textured black shark fin stone guards. These are much thicker than PPF, so they need to come off before you fit MagnaFins or WrapFins.

PPF and ceramic coatings. No problem at all. Both types can be fitted over paint protection film or a ceramic coating.

How to fit MagnaFin stone guards

We fitted a set of magnetic MagnaFins to a 986 Boxster S in our R&D workshop to see how they go on. It only takes a few simple steps.

1. Clean the panel. Use a panel cleaner to get all the dirt and grime off the area around the arch. Any bits of debris left on the paint could get trapped under the guard and scratch it.
2. Check the back of the guard. Because MagnaFins are magnetic, they’ll happily pick up metal filings and grit if you put them down on a workshop floor or bench. Make sure the side that goes against the car is completely clean.
3. Put it in place. MagnaFins are really flexible, so they bend to follow the shape of the arch as you lay them on.
4. Smooth it flat. Run a microfibre cloth over the whole surface to push out any air pockets before you drive.

And because they’re magnetic, they come off just as easily as they go on. That means you can swap between finishes whenever you fancy a change. On our Boxster, we switched to a Carbon Fiber set to see how it looked.

You can watch Claudia fitting them over on the Design911 Instagram.

FAQs

Will MagnaFins stick to my car?

They’ll stick to steel panels. The 718 and 992 have aluminium rear panels, so they need WrapFins instead. If you’re unsure, test the area with a magnet before ordering.

My rear arches have been repainted. Will MagnaFins still work?

Possibly, but refinished panels can have body filler and thicker paint than factory panels, which can reduce the hold. Test with a magnet first. If it doesn’t stick firmly, go for WrapFins.

Can I fit them over PPF or a ceramic coating?

Yes, both MagnaFins and WrapFins can go over PPF and ceramic coatings.

Do I need to remove my old stone guards?

Not if they’re clear PPF-style guards, as both types can go over the top. The thick black shark fin guards found on many G-Series and 930 Turbos do need to come off first.

Do I need to take MagnaFins off to wash the car?

Yes. Clean them with whatever you use on the car and refit once both are completely dry.

How do I remove WrapFins?

They peel off in one piece without heat or a scraper. If you remove them carefully and store them on the included wax paper, you may be able to reuse them.

Find the right MagnaFin for your Porsche

Whether you want magnetic guards you can fit for a weekend away or WrapFins you can leave on all year, there’s a MagnaFin option for most Porsche models. Browse the full range, pick your model and choose your finish.

Shop the MagnaFin range