Rated lifespan vs. real-world lifespan
Manufacturers rate coatings by years — 2, 5 or even 9 — but those numbers assume ideal care. In Greater Boston, where cars face road salt from November to April, summer UV and pollen, real-world lifespan sits toward the lower-middle of each product's range.
Water behavior is the easiest gauge: tight beading and fast sheeting mean the coating is healthy. When water starts to sit flat on the hood and roof, it is time for a decontamination wash and a top-up.
What shortens a coating's life
Brush tunnel washes abrade the coating, high-pH touchless soaps degrade it, and letting brine sit for weeks clogs the surface. Bird droppings and tree sap left in summer sun can etch even coated paint.
How to make it last
Use a pH-neutral shampoo with the two-bucket method, dry with a plush microfiber towel, and apply a silica (SiO2) spray topper every few months. An iron decontamination twice a year removes embedded brake dust and rail dust.
Horizontal vs. vertical panels
Hoods, roofs and trunks take the most UV and contamination, so they show wear first. Many detailers apply an extra layer to these panels for that reason.
