Firstly your wheels - if you use a paint pot and brush whilst still on the car, it will look like a very amateur job IMHO. Best if you can to remove the wheels, mask everything off, thoroughly clean and degrease, then use a grey primer (fiver a can), then your desired colour. Some people smirk at rattle cans but if your preparation is good, it can bring excellent results. You also have a good range of colours and 2 or 3 cans will probably be enough if you have primed it well. Look on Youtube for how-to guides. At the very least, if you can't get the wheels off then mask everything properly, don't get any on your brake parts!
Car washing - we have several drive-in hand car washes. Inside and out can be done for about £25. They do a good job (there's a gang of 5 of them that descend on your car and are finished in about 10 mins). You can pay for any extras you want (pfnar), much better than a machine wash