An APC, as implied by the name, is a general cleaner to be used on all areas of a car, including the alloy wheels, engine bay, exterior surfaces, and even the interior. With a mix of basic surfactants or detergents for the cars and other motor vehicles; they are effective at removing most dirt and grime. Some may be a little stronger to tackle the exterior specifically. Most APCs can be diluted to use on more delicate surfaces such as fabrics and interiors, it is always best to do patch tests on and surfaces that have dyes to insure compatibility.