Although many car parts are not seen on the surface, it's important to keep everything as clean as possible including the wheel wells. Firstly, what is a wheel well? This is the part that surrounds the wheel and tyre from behind thus making a protective enclosure and space for the tyre to fit in.
Before starting with this particular job, remove the tyre and wheel from the axle to manage a proper and thorough clean. Many people make it a monthly task to keep this part of the car clean. The chances of grease and dust particles getting embedded are quite high; which could make for an unpleasant drive in the future. This might not cause any major damage but any dust particles in the mechanisms would be noticed.
Many people prefer to do a simple wash with a high pressure hose because it takes less time. There is no problem with this type of wash but it won't be good enough if you are going to add a coating of paint to protect the metal.
When using industrial cleaning products, make sure that you use non-wax chemicals to avoid having an unpleasant and pointless finish. The best type of cleaner to use for this job would be a water based product to avoid corroding of the metal and unnecessary rusting.
Before fitting the wheel back in place, scrub the entire inside of the well with a brush to loosen the tougher particles. The dirt may also attach onto the enamel pieces so make sure that you do all the necessary painting before putting the wheel onto the axle again.
People who do customisations prefer to use a wheel well liner to avoid cleaning the cracks and crevices in this difficult to reach place. The liner doesn't cover the entire well but rather the gap that needs to be kept from air exposure.
The liner is also easier to clean. With this component, give it a quick dust off and wash it with water or an aqua based cleaner. Over time it may also lose some of the paint so to keep it looking fresh and new, apply the proper paint or coating when necessary.
Cars are important machines in this day and age which need constant care, cleaning and maintenance. If you are unsure about how to do a certain car related task, it would be ideal to ask assistance from someone who is familiar with tyres or vehicle maintenance.