“It’s a new car — it won’t rust for years.” Unfortunately, that is not always true, even for the newest cars on the road.
A few years ago, owners of one of the world’s best-selling new electric cars began reporting corrosion within months of delivery — enough of them that owner groups formed to compare cases. Inspections traced much of it to thin or incomplete paint coverage around door hinges, pillar edges and panel joints: places where bare metal met road spray. The manufacturer later added a note to the owner’s manual recommending that owners rinse road salt from the underside of the car.
That story is not unique to any one brand. Every manufacturer builds to a price, and factory corrosion protection is thinnest exactly where rust starts: inside box sections, seams, hinges and the underbody areas hit by stone chips. A car can be rust-free on the outside while corrosion quietly starts inside a sill.
That is why the best time to protect a car is when it is new — before the first winter, before the first stone chips, while every cavity is still clean and dry. A cavity wax like Mercasol 1 creeps into seams and hollow sections, and an underbody coating shields the areas the factory paint barely covers.
New car? This is the cheapest insurance it will ever get. See the range.