Brake Fluid Leak problems of the 2008 Mercedes Benz C300

This issue surfaced while driving and brakes where applied. Lost breaking due to corrosion perforating rear brake lines causing break fluid to leak and total loss of breaking. This is a 2008 c class 4matic sport where both rear brake lines feeding from the abs module to the rear calipers were totally rusted and caused the car to loose all braking. Brake lines rusted mostly where they are attached to the frame under the car due to sub par quality of the metal used and moisture trapped between the bracket and the brake line. I own two other cars that are 22 years old with no rust on the brake lines and driven in the same exact environment as this mb C300. Repair cost at an independent shop ran $1600.