2010 Mercedes G550 rust around the windshield and door sills
JD101b reported corrosion on a 2010 G550 with 55,000 miles, including areas around the windshield, rear-door hinges and door sills. Some sill spots had already been repaired, but the wider problem remained unresolved; another owner described a separate G55 windshield-frame repair.
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Rust bubbles on a 55,000-mile G550
JD101b described a well-cared-for 2010 G550 developing rust bubbles below the front windshield, around the rear-door hinges and along the side-door sills. He was discussing the problem with Mercedes and asking how to protect difficult-to-reach areas in the long term. His question covers both existing corrosion and prevention; it does not document a completed repair for all those locations.
Some door-sill spots had already been repaired
In a follow-up, JD101b said MBUSA had already repaired several spots on the door sills. He described the earlier sill corrosion as being on the passenger side and suspected new corrosion on the driver’s side. That suspicion was not a confirmed diagnosis. He supplied the close-up photograph shown here and said the other areas were too small to show clearly in photos; the precise body location in this image is not identified.
Drying and lubrication were the owner’s current measures
The owner initially described weekly hinge lubrication with LPS, a garage dehumidifier and fans drying the underbody. In a later post he described a dehumidifier set to 15%, circulating fans and WD40 around hinges and windshield rubber. These are his reported settings and product choices, not evidence that corrosion stopped or that the measures are suitable for every location.
The underbody coating sequence was still a plan
JD101b wanted to sand surface rust from the chassis, apply a rust converter and several coats of flat enamel, then add Fluid Film or LPS after curing. He remained concerned that door-sill cavities, the windshield area, rear hinges and the sunroof area would be difficult to treat. The post presents intended work; it does not report completing or testing that coating sequence.
A different 2010 G55 needed more extensive windshield-frame work
drew138 described rust bubbles below the windshield on his own 2010 G55. He said Mercedes initially agreed to a repair estimated at $2,500, but dismantling revealed more extensive corrosion and the work ultimately involved welding in a new frame around the windshield. He reported that Mercedes headquarters provided input on maintaining structural integrity. This is a separate vehicle and a reported repair scope, not proof that the photographed G550 needs the same work. The final repair cost was not stated.
The cause and a lasting preventive solution were not established
JD101b later asked whether the underlying issue concerned paint, metallurgy or something else. That question does not establish a technical diagnosis. drew138’s belief that some 2010 Gs had a systemic issue remains his opinion based on his experience; these accounts do not establish a failure rate, a common root cause or a verified rust-prevention method.