Wheel Arch Rust

[eck c]

Was quite surprised to find rust bubbles appearing on the forward facing part of the rear arches on Mrs. C car, it's a 2015 CLA Shooting Brake.

Is this a known issue with Mercedes?

[Toffer]

Could it be a poor quality repair by a former owner?

[donkmeister]

It's a classic place for stone damage, and is low enough that it's easy to miss until you're down there looking at something else.

I had a car which had very early signs of bubbling on the rear arches. Despite me regularly hand washing it and having replaced the rear brakes a few months prior, I only spotted it when a prospective purchaser asked me over the phone if it had any rust around the arches. Being an honest sort of chap I got down on my hands and knees, gave it a damn good looking at, and there it was. Barely visible but definitely something happening under the paint. Wouldn't have spotted it if he hadn't asked.