A good all-purpose cleaner, or APC, is the Swiss army knife of your detailing kit. Diluted for upholstery and door jambs, a bit stronger for rubber and plastics, and for stubborn dirt you can increase the concentration without reaching for a separate product.

The advantage of an APC over ready-to-use sprays is flexibility. One bottle of concentrate replaces a whole shelf of individual products. As long as you match the dilution to the surface, you can use it everywhere inside and outside the car.