How to detail your exterior trim

When most people think of a clean car, they think of shiny paint. But any expert detailer will tell you that the secret to a truly stunning vehicle lies in the details. Specifically, the exterior car trim.

Over time, the plastic, rubber, and vinyl components around your windows, bumpers, and wheel wells can become "chalky" or faded due to sun exposure. At Carma, we believe exterior car detailing is the best way to preserve your car’s value and aesthetic. This guide will walk you through how to clean, restore, and protect your trim to keep it looking brand new.

What is the exterior car trim?

The exterior car trim refers to the non-painted accents of your vehicle. This includes:

• Plastic & vinyl: Bumpers, side mouldings, and mirror housings.
• Rubber: Window seals, door gaskets, and windscreen wiper blades.
• Polycarbonate: Your headlights and taillight housings.

These materials are porous and sensitive. Unlike your car's paint, which has a clear coat for protection, trim is often "naked" and highly susceptible to UV degradation, causing it to turn from deep black to a dull grey.

Why should I take care of my car trim?

While a professional detailer does a great job, learning to detail your exterior trim yourself has major perks:

1. Cost savings: You avoid high labour costs and only pay for the products, which last for dozens of applications.

2. Longevity: Regular maintenance prevents the plastic from becoming brittle and cracking, which can lead to expensive leaks in window and door seals.

3. Resale value: A car with deep black trim and clear headlights always fetches a higher price than one that looks weathered.

What you’ll need

• pH-neutral car soap: Gentle enough for both paint and rubber.
• Trim protectant: A dedicated plastic restorer or UV protectant (avoid silicone-based "greasy" dressings).
• Wax remover: To get rid of white stains left by previous waxing sessions.
• Detailing brushes: Soft-bristled brushes for honeycombed grills and crevasses.
• Microfibre towels and/or wash mitt: Essential for a scratch-free finish.
• Clay bar kit: To remove embedded grit from the trim and glass.
• Two buckets: One for soap, one for rinsing.

Step by step guide

1. Debris removal and prep

Start by using a vacuum or a blower to remove leaves and twigs from the base of the windscreen and the wheel wells. Use a wax remover on a microfibre cloth to wipe down plastic trim pieces. This removes old polish residue like those annoying white streaks that soap alone won't touch.

2. Inspect your components

Before getting wet, check your windscreen wiper blades. If they are cracked or leaving streaks, they should be replaced. You should also inspect your headlights; if they are cloudy, they may need a specific headlight restoration polish.

3. The two bucket wash method

To prevent scratching your paint, use the two-bucket method. Fill one bucket with soapy water and the other with plain water.

• Dip your mitt or cloth in the soap, wash a section, then rinse the dirt off the mitt in the plain water bucket before going back for more soap.
• Always start from the roof and work your way down. This prevents dirty runoff from contaminating areas you’ve already cleaned.

4. Deep clean with a clay bar

After washing, your trim and glass might still feel "bumpy." Follow our guide on how to use a clay bar to pull out microscopic contaminants like industrial fallout and tree sap. This creates a perfectly smooth surface for your protectant to bond to.

5. Drying

Never let your car air dry! This causes water spots to form. Use a large, clean microfibre towel to pat the car dry, paying close attention to the window seals where water likes to hide.

6. Restore and protect

Once the trim is dry, apply your trim protectant.

• Apply a small amount to a sponge or applicator.
• Work it into the plastic and rubber in circular motions.
• Let it sit for a few minutes, then buff off the excess with a clean cloth. This creates a UV barrier that prevents the sun from bleaching the material.

Pro tips for a perfect finish

• Don't forget the tyres: Use a dedicated wheel brush to remove brake dust. A clean tyre makes the rest of your trim look even better.
• Avoid the sun: Always detail your car in the shade. Heat makes chemicals dry too quickly, leading to streaks.
• Under the hood: While you have your cleaning supplies out, why not clean your engine bay too? A clean engine and clean trim are the hallmarks of a well-maintained vehicle.