Corrosion protection is offered in two forms: conventional spray and an electronic rust control module. Conventional sprays now are tar-based or oil-based (either dripless or drip), and provide a hardened barrier to the underside of the car. They require you to check occasionally for cracks that can allow moisture through the barrier, and are the most common form of rustproofing provided when buying a car. Electronic rust control modules are a devices installed on your car that forces a protective flow of electrons into the metal that needs protecting.
Both are viable products that should be considered when making your decision to rustproof your car or not. There are a few factors that should be weighed:
- Long term plans. How long you plan on keeping the car? If you want it to be your car for more than a few years, rustproofing your car is more than worth the cost and will save you a lot of depreciated value and repair costs in the long term.
- Your location. If you live in a colder climate area that uses a lot of road salt during the winter, rustproof is a must.
- Your warranty. Most domestic and imported vehicles will provide coverage for rust-through on your car for five years, maybe more.
These factors will help you determine if you want to get some type of rust protection or not, and what type/how much you want to spend if you do choose to get rustproofing.