Fixing Sun-Damaged Exterior Plastics

Wash the whole car first, but focus on the plastic. Spray your APC liberally and agitate it with your brush. You'll see brown gunk coming out, that's oxidized plastic and old road grime.

Dry the trim completely. If it feels slick or greasy, clean it again. It needs to be bone dry and 'grabby' to your finger.

Tape off the paint edges. I learned this the hard way on a white Commodore, most restorers have a black dye in them, and if it gets into your clear coat, it's a nightmare to polish out.

Wipe the trim down with your IPA mix. This pulls out any remaining silicones or waxes that 'protection' washes might have left behind.

If you're using something like Solution Finish (which I reckon is the best for older cars), shake it like it owes you money. The pigments settle at the bottom.

Put 2-3 pea-sized drops on your applicator. A little goes a long way. Don't soak it, or you'll get drips.

Start with a 30cm section. Massage the product into the pores of the plastic using circular motions, then finish with straight passes.

Wait about 1-2 minutes (less if you're working in a hot garage), then buff the excess off with a clean microfibre. If you leave it too long, it gets streaky.

Step back and look at it from an angle. If it looks patchy, give it another light coat immediately.

For heavily textured trim, use a 'stippling' motion with the applicator to make sure the product gets into the valleys of the plastic grain.

This is crucial. Keep the car out of the rain and don't wash it for at least 6-12 hours. If it gets wet too soon, it'll spot and you'll have to start over.

Pull the tape off at a 45-degree angle while the product is still relatively fresh to avoid any hard lines.