Exterior Cleaning

With the wheels. They're the dirtiest part and take the strongest product - leave them until last and they'll splash bodywork you've already washed. Then comes the pre-wash to remove loose dirt, decontamination of bugs and tar, the wash with shampoo and mitt, drying, and only at the end, protection.

1. Wheels and tyres - wheel cleaner and a dedicated brush, with the wheel cool.
2. Pre-wash - plenty of water to carry away sand and dust before any cloth touches the paint. This is where fine scratches are prevented.
3. Decontamination - bugs, tar and sap come off with a dedicated product, not with shampoo.
4. Wash - shampoo, wash mitt and two buckets: one with suds, the other just for rinsing the mitt.
5. Drying - microfibre towel, no rubbing. Letting it air-dry is what leaves water marks.
6. Protection - wax or polish to seal and keep the shine.

You use a small cupful per bucket, so any size goes a long way. If you wash your car once a month, the litre is enough. If you wash every fortnight, have more than one car at home, or also wash your motorbike, the 5 L works out much cheaper per wash.

• Wax - protects and makes water slide off. It doesn't correct defects; it goes on top of paint that's already clean.
• Polish - revives the shine and hides very light marks. It's the in-between step.
• Polishing compound - corrects fine scratches and oxidation. Only use it when there's a real defect to remove, because it works the clear coat.

Rule of thumb: if your fingernail catches in the scratch, polishing compound alone won't fix it.

Rain repellent doesn't clean - it forms a film that repels water from the glass, so it always goes on after the glass is clean.

Redex chemistry, made by Plurifil in Rio de Mouro, Sintra, Portugal. See also exterior cleaning and cleaning accessories.