The consistently named structural weakness is rust, driven by a design quirk: the chrome trim strips ahead of the rear glass drain water into the hollow rear fenders where dust and moisture collect. Owners in salt or wet climates report the rust 'got to it,' and prospective buyers treat rockers, wheel-well members and undercarriage as the critical inspection points.
Rust and water traps in the rear-fender corners
Mercedes-Benz 190/200/230 Fintail (W110) · mechanical