The heater core on my '91 190E 2.6 let loose dramatically one day on the freeway. There was a huge cloud of steam out of the center vent and a deluge on the carpet on the passenger side. After a $100 tow back to my mechanic I was quoted about $700 to replace it. Since I live in the desert and normally don't drive this car in the evenings, I put the repairs off for the last couple of years. Now I am selling the car to my granddaughter who lives in a cold part of the state. I ordered the core from Fastlane ($129) and my new mechanic will install for $500 The car had about 130000 miles on it at the time.