Hi. My son just bought a 2015 Mazda3 iSport 4-door sedan.

He didn't get any pro protection at the dealer but he would like to know if an aftermarket undercoating/rustproofing would help stop any rust that may form over the years?

He lives in Vermont where the winters are mean and the road salt is used profusely.

From what I can find about rustproofing, there are a couple different ways it can be applied.
1) Spraying it on the underside of the vehicle.

2) Spraying the underside of the car and drilling into different areas of the underside of the car to get the rustproofing "inside" certain areas of the car. Maybe even drilling into the doors where people say that's where most of the rust starts-inside the panels.

The reason I'm asking about rustproofing is we owned a 2003 Mazda Tribute and never had it undercoated. Probably around 2010 the rust was really showing it's ugly face and we needed to repair the rocker panels, lots of rust was in the wheel wells area, rust on the underneath of the car, etc...

Any help/advice on this subject sure would be appreciated.
He loves his new car

Thanks,
His Dad......

 

rustproofing is a must. The only method that doesn't work is those ridiculous electronic modules!
Some methods are more messy (oil drips), others not so much. Needs to be inspected and updated every year.

 

Since the car is new, undercoating is worth doing for rust and winter salt protection.

 

Plus you will get a good warranty from aftermarket company