Stains

A stain is discolouration of the paint's surface. It is not easy to stain a car's paint, however damaged, etched or 'dead paint' which results from oxidation is more porous and can hold compounds which may appear as stains.

Stains might also occur via solvent migration, such as plastic items being left on the car for long periods of time. 

What it means

Stains are marks that change the colour or tone of a surface rather than simply sitting on top of it as loose dirt. On paint, you might see water spots, bird-lime etching or traffic film staining that leaves dull patches. On interiors, stains can be drink spills, food marks, dye transfer from clothing, ink, makeup or sun cream that has soaked into fabric, leather or plastics. By definition, a stain does not come away with a basic wash or quick wipe and needs targeted cleaning or, in some cases, physical correction to improve.

Why it matters

• Very noticeable on otherwise clean cars: A few stubborn stains on a bonnet, seat or carpet stand out more once the rest of the car is clean.
• Can be permanent if left: Bird lime, hard water and strong dyes can chemically attack paint and interiors, making the discolouration harder or impossible to remove if they are ignored.
• Determines the right treatment: Some stains can be cleaned with the right chemical, while others need machine polishing, wet sanding or even recolouring or replacement.
• Affects value and presentation: Obvious staining on high-touch areas like steering wheels, seats and bonnets makes a car feel tired and can reduce resale appeal.

Where you’ll see it

You will see the word “stains” on inspection reports, detailing estimates and condition appraisals – for example bird-lime stains on bonnet, hard water staining on glass, dye transfer staining on leather or drink stains in carpets. Service menus may refer to stain removal, odour and stain treatment or stain-guard protection for interiors.

Context

In detailing language, stains sit alongside scratches, oxidation and fallout as common problems that need more than a quick wash. On paint and glass, many stains are actually mild etching in the surface and are treated with specialist cleaners, machine polishing or, in heavy cases, wet sanding. On interiors, stain removal is usually a combination of the correct chemistry, dwell time and extraction, sometimes followed by recolouring or re-dyeing where the original pigment has been damaged. Protection products such as sealants, ceramic coatings and fabric or leather protectors help resist future staining but cannot always undo existing damage.

Common mistakes

• Scrubbing stains aggressively with harsh brushes or scourers and adding scratches or wear on top of the original discolouration.
• Using the wrong chemicals – for example strong solvents on leather or harsh acids on paint – which can fix the stain in place or damage the surface further.
• Leaving bird lime, fuel spills or hard water deposits on the paint for weeks, allowing them to etch deeply into the clearcoat.
• Expecting every stain to disappear completely, even when the underlying material has been bleached, burned or dyed and really needs recolouring or replacement.

Written by Danny Argent. Last updated 19/11/2025 15:32