Once you have thoroughly cleaned and repaired the various parts, you are now ready to respray. Once the model is clean try not to contaninate it with fingerprints. You mast have a well ventilated area, free from dust. The model is best kept on a small vice thingy, as in the picture.
Spray paints are best used sparingly with constant movement. Try not to hold it stady to get the hidden corners, use it like a crop sprayer, sweep, dive and move on. Several light coats are better than trying to do it in one. With practise, once you see the paint start to gloss stop, one more pass it will run.
Always use a primer, and more than one coat, with a light rub with fine wet and dry
Two or more top coats can be applied but don't do more than is necessary. Follow the basic respray techniques as above. Just enough to get a gloss, keep the spray can moving at all times.
If the model requires a second color, do not try to mask up until the first color is dry, leave overnight at least. Cut the masking tape into thin strips to get around corners, stretch it slowly, you may have to do this several times. Use sufficient to cover the first color and firm down the edges with a fingernail, or an edge of a flat screwdriver. IMPORTANT, do not try to get a gloss on the first pass, the paint will likely get under the masking tape. The first coat should act like a seal, once dry, add two more coats. Once the paint is just dry, peel off the masking tape, and leave alone to fully dry. Touch up by spraying a little paint into a container and applying with a brush.
Headlamps, tailights, grill. Your own choice here, but add sufficient paint to the brush, so not to drag but not so much as to blob and run. Other details such as red for the back lights, painting the driver, etc. I use acrilic from the dollar store.
Depending on the standard you wish to get to, removing the axles and wheels from the chassis is not always necessary. I spray the whole thing with primer and top coat for the wheels. Then I mask the wheels, spray the chassis, and finish off the axle ends with a wet and dry or polish them off with a rotary tool. If you do remove the axels, replacng them is covered on the AXLE page.
I rarely do this but you can apply a lacquer to the model to protect it.