Preparation
Cars that still have a glossy look to them need to have the shine removed so that paints and glues will work properly on them. The most expedient way to accomplish this result is to spray the cars with Dullcote. Two coats of this paint will usually do the trick, and should leave the car with much less shine, and a paintable surface to boot.Detailing
This step is totally optional, though I find it produces better looking vehicles, and when you're blowing up other drivers in the desert, style is all that counts. This step involves painting color onto certain molded, unpainted details on the car. This can include headlights, grillwork, and door handles. This part would also include any changes you wish to make to the body color of the car, such as repainting the hood. High quality brushes and patience are needed here, in order to keep from painting over the wrong parts of the car, but the end result is well worth it.Modifications
This step is where you will attach any weapons, armor, or other odds and ends to the vehicle. The step really is self explanatory. The only good modeling tip that can be given here is to use a form of superglue to make the attachments, as normal glues do no hold and are often dissolved by the paints. My personal favorite si Quiktite, and I can make about six cars to a bottle. Be careful not to glue your fingers together here. Superglue is not a toy.Weathering
This is it, the final step on most Axles and Alloys vehicles. Weathering involves two steps. The first step is to apply dirt and mud where you see fit. This is done via drybrushing, the details of which are far too complex for this site. However, the basic idea is to get paint on the brush, then wipe most of it off on a towel, leaving only a chalky sort of paint residue on the bristles. You then paint this lightly over the areas you wish the mud or dirt effects to be on. Simple, no?