A car that may or may not have undercoating.
Photo: Señor Salme

Q. I just bought a new car and declined the $800 protective under­coating that the dealer was urging me to get. Did I make the wrong decision?

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A. The short answer is no. Cars today are manufactured with corrosion protection, which makes this added treatment unnecessary, though it is profitable for car dealerships. Consumer Reports recommends that car buyers skip the undercoating and several other pricey add-ons, including VIN etching, fabric protection, and extended warranties.

Editors Note: This article also appeared in the September 2018 issue of Consumer Reports magazine.