Car Washing Guide
Even if you are not particularly interested in your car having a spectacular shine, you should still wash it regularly. As well as the obvious factor that dirt just makes your car look untidy, it can also hold moisture against the bodywork, which can lead to corrosion. Also, in the winter months there is a lot of salt on the roads, which is particularly bad for corroding metalwork.
The best way to start is to give your car a pre-soak by running water over it with an open hose. This will let the water soak into the dirt and soften it so it breaks up a bit easier. You don't want to use water under high pressure from either a pressure washer or a hose jet because this could force the dirt across the surface of the paint and scratch it. If you need to remove large lumps of dirt with a jet, you should soak them for a while first to soften them up. You can also get products which you can use as a pre-wash, either spraying onto dirty areas directly, or mixing into the water you soak the car with. You should also get rid of the dirt from other areas, such as under the wheel arches.
Leave the dirt to soak for a while. You should wash your car away from direct sunlight so that the water doesn't dry off before you want it to - the car should stay wet until after you've finished washing it. If it dries early, you can end up with blotches in the paint.
You will now need two buckets, one with warm water mixed with a car detergent as directed by the instructions on the bottle. The second bucket should contain plain warm water. The reason for two buckets is so that you can use a microfibre wash mitt in the first bucket to apply the soapy water to the car, and then you rinse it out in the second bucket so that any dirt you've removed is not returned to the car.
You should use a microfibre wash mitt rather than a sponge because a sponge will hold any dirt against the paint surface as it's being washed, causing scratching. A microfibre wash mitt lifts the dirt away from the paintwork and traps it in its fibres so it doesn't cause scratching.
The best approach to washing the car is to start with the roof and move around the car, gradually working downwards in a kind of spiral. This is so that gravity will wash the dirt away from areas which you've already cleaned. Also, the dirtiest areas are usually at the bottom around the sills, so it's best to leave these until last. In fact it's sometimes a good idea to change your water before you wash the dirtiest areas. You should be lifting the dirt off rather than scrubbing at it. If you have stubborn dirt like tar or tree sap, it's best to remove these later using clay bar.
After washing, rinse the car using water from an open hose rather than a jet or pressure hose. This will let the water run off as one mass, rather than breaking up into droplets and staying on the car.
To dry the car, you can either use a microfibre towel or a chamois leather. You should be careful not to be to aggressive with the drying since this could scratch the surface. You can avoid this by laying the towel or chamois flat, and then dragging it across the surface, so that it only has the pressure of its own weight. Or if you're using a towel, you can pat the car dry and avoid any kind of dragging.