I don't clean my car. But when I do - I clean it. I take out seats, centre console, carpet... I wash out the spare tyre well in the cargo area. I cleaned the roof lining with a melamine block and a bucket of dishwashing detergent when I first got my wagon and the change in colour was scary. I wash the paint with cheap car detergent and use a PVA chamois to dry it. The clear coat is almost non existent so I don't wax it. I do however remove the aftermarket 16" alloy wheels and strip them inside and out. I use alkaline based oven cleaner* to break up brake pad dust and remove the ozone browning on the tyre walls, then pressure clean them, then wash them with regular car wash detergent before going over them with a polymer clay rubbing block and a wax. I use the cheapest car wash detergent, paste waxes and tyre shine spray and no matter how beat up my wagon is it still looks good.
*The alkaline oven cleaner is great for cleaning wheels and degreasing engines. I used to buy kerosene based aerosol degreasers and not only was it expensive, messy and smelled bad but it would also make a mess of the driveway (being highly flammable was an added bonus) I can use one can of oven cleaner and it will rip oil and gunk off an engine and bay and leave me enough to do another engine no problem. Spray it on, break it up with a brush and blast it off with a pressure cleaner. It has to be alkaline based. Caustic, lye or sodium hydroxide based oven cleaner will wreck your car. The alkaline stuff is safe enough to spray on your hands (it does a magnificent job of getting greasy hands spotlessly clean in no time) When you rinse it off, it sort of granulates the oil and gunk into a black grainy looking residue that doesn't stick to anything.
*How to know what you're actually using to wash your car with. Every cheap car wash detergent has carnauba wax dissolved into it. This is what makes your car look shiny after it's dried. The problem with using this is the wax also bonds to the glass and it's a lot of work to get it off. If the detergent smells slightly sweet - that's carnauba wax. Nothing wrong with it. I never use expensive brand name car wash as I can't justify the price, but the good stuff doesn't contain soluble wax.
*polymer/clay rubbing blocks. I thought it was some weird gimmick - until I tried it on wifeys' car. If your car has decent, solid paint I can't recommend it enough to buy a rubbing block and giving your ride a going over with it. Turns tired and dry feeling paint into glass. This is the step that elevates your car when you apply wax. It is a long process to go over your entire car but the end result is worth it. You can get about 4 treatments out of one block depending on how bad the paint is contaminated.
