All waxes require elbow grease, patience, and time. Depending on how fast you work, how thorough you are, the size of your vehicle, and the product you choose, expect to spend at least an hour to do a decent job. Match the car wax to your car-care needs to see which type of product best suits your needs.
Consider the age of your car. If Itís one or two years old or still has a good finish, an easy spray wax might be all you need. But keep in mind that these products wear out the fastest. No wax will improve the shine on a newer car. But if you donít plan to replace your car for a while, waxing will help preserve the finish over time.
If you have an older car, or one whose finish has already begun to oxidize or has embedded grime, you may want to consider a product that scored high for cleaning to help bring back and maintain the finish. Liquid waxes proved the best in cleaning.
Watch out for abrasion. Waxes can be abrasive, some more than others, and the tiny particles in car waxes or harsh chemicals can leave fine scratches or a haze on your carís finish.
Dark-colored vehicles show scratches more easily than lighter-colored ones. If you own a black or dark-colored vehicle, be especially wary of products that scored low in our scratching and hazing tests.
The same abrasiveness can make clear-coated surfaces look hazy or cloudy when the finish is marred by fine scratches, giving the paint a duller look than before waxing. Most wax packaging indicates whether a product is safe for clear-coat finishes.
Consider how much plastic is on your car. Some waxes can leave a visible residue on nonglossy, porous plastic parts such as bumpers, plastic body panels, and door trim. Those parts are often black or gray, and some newer cars may have a lot of them. If that sounds like your car, choose a product that scored well in our compatibility-with-plastic tests. Once wax gets on those surfaces, it may be necessary to use a commercially available plastic cleaner to get rid of it.
If saving time and effort is your priority and your carís paint is in excellent condition, a spray-on, wipe-off product may be your best bet. Spray-on waxes can also be used for a quick touch-up between conventional waxings. These waxes donít clean as well as or last as long as liquids or pastes, but thatís not an issue if you wax often. And the more often you wax, the more youíll appreciate their ease of application.
With any wax you choose, it is recommended you first try using it on an inconspicuous area such as a doorjamb. And regardless of how hard you work, how much you spend, or what longevity claims manufacturers make, donít expect any wax to last all that long. All of the products tested showed a significant loss of protection within about five weeks.
Source - How to choose