Vehicle undercoating is simply a coating that is added to the metal parts underneath the car. Sometimes this is done at the dealership, and sometimes you can find independent shops that will offer this service. However, there are both pros and cons to car undercoating.

Pro: Decreased Noise

The thick coating applied to the bottom of the car will help to minimize noise from gravel and other materials hitting the metal on the bottom of the car. Although many cars are pretty quiet these days, the decreased noise can still be noticeable. The extent to which the noise will be decreased will depend on the type of car.

Pro: Rust Prevention

The main use for car undercoating is to limit rust in the bottom of the car. Vehicles usually come from the factory with some rust-proofing already added, but if you plan to keep your vehicle for more than three to five years, it may be a good idea to get the best undercoating for trucks. It makes the most sense when you live in an area that is salty, such as areas by the ocean and those that use a lot of salt on the road in the winter. Salt can increase the risk of rust. Paint protects much of the car, but the bottom of the car isn't painted, making it a little more vulnerable to rust.

Con: Potential Warranty Issues 

Some car warranties specifically state that having a third party undercoat the vehicle voids the warranty for rust damage. This is because a poorly done undercoating job can actually trap water and salt and increase the risk of rust. Check your warranty to make sure you choose an approved company to apply the coating.

Con: Best If Professionally Applied

Depending on the who applies this coating, it can be quite expensive. Some dealers include it in a package, rather than offering it separately, and charge anywhere from $200 to $1,200. It's possible to buy a do-it-yourself kit, but keep in mind the potential risks of messing up the coating, which is one reason why it may be better to have this job professionally done. If you try to undercoat your vehicle yourself, you'll need to make sure that it's perfectly clean first or the undercoating won't stick. Also, be careful not to coat any drainage holes; it can damage your car if these are blocked. It is a bit of a pain to do this process yourself, so many people recommend using a professional.