How to remove salt stains from car carpet and mats

Salt stains are not dirt. They are chloride crystals left behind when slush from your boots melts into the carpet and dries. Because the salt is in the fibre and the backing, not on the surface, a vacuum does nothing and scrubbing just spreads it. And because chloride pulls moisture out of the air, the stain re-crystallises after every humid day, which is why it seems to come back. It is not coming back; it never left.

The home method that works

1. Vacuum the loose crust first, with a stiff brush to break it up.
2. Mix one part white vinegar to two parts warm water in a spray bottle. The acid dissolves the alkaline salt deposit.
3. Spray the stain until damp, not soaked, and let it sit five minutes.
4. Blot with a clean towel, pressing, not rubbing. Repeat spray-and-blot until the towel comes up clean.
5. Rinse with plain warm water and blot again, so no vinegar is left to attract its own dirt.
6. Dry it fully. Doors open on a dry day, or a fan. Damp carpet over a steel floor is how rust and smells start.

What makes it worse

• Scrubbing hard, which frays the fibre and pushes salt deeper.
• Soaking, which drives the salt into the backing and the padding, where it stays.
• Carpet shampoo alone, which cleans the dirt and leaves the salt.

Why the professional version is different

A hot-water extractor sprays a cleaning solution into the carpet under pressure and immediately vacuums it back out, along with the dissolved salt, from the backing as well as the surface. That is the difference between moving the salt around and removing it, and it is why a spring interior detail leaves carpet that stays clean through the summer instead of blooming white again in July. We do the mats, the carpet, under the seats and the trunk. Interior detailing.

Preventing next winter's stains

Rubber or tray mats catch the slush before it reaches the carpet, and can be shaken out weekly. Keep the carpet mats for summer. The full winter checklist.