NHTSA Complaint #11679081 — 2012 MERCEDES-BENZ E350

I recently took my 2012 Mercedes-Benz E350 to an authorized Mercedes-Benz dealership after experiencing corrosion of the rear subframe. The dealership confirmed and is servicing the vehicle under an active recall notice that extended the original New Vehicle Limited Warranty from 4 years/50,000 miles to 20 years /unlimited miles. After removing the subframe for repair, they observed serious corrosion of the brake lines. There had been no warnings or symptoms to alert me to any corrosion problems with the brake line prior to this. Most likely, the issue would not have been discovered if the dealership had not removed the subframe. The dealership advised me that this issue requires immediate service due to safety concerns (potential failure) as the braking system could fail while driving the vehicle. The cost to have the work done is $5800. Beyond the dealership service center, I'm not aware if brake line has been inspected by others (engineers) in Mercedes-Benz. However, this issue appears to be frequently observed in vehicles experiencing the rear subframe corrosion issue.