FYI- I own a Black/Black M5 I keep this car up very well and got tired of the heater control valve problem almost every year. I read on myE28 that the aftermarket replacement valves are not designed correctly and that's why they fail. Some say the MB valve is better. So I decided (while you can still get it) to buy a whole new valve from BMW. Yes, it was $300. Installed it last Monday drove the car a little on Friday and then went for a spirited mountain drive on Saturday. While I was waiting for the rest of the cars to show up I parked on a little bit of a hill in a mall parking lot. I looked back 20 minutes later and see a puddle running down the hill. Looked at valve and see water coming out a seam just above where the hose attaches. Looks like valve is bad. I did get to do the drive. It was not leaking that much and drove for a couple hours and then added some water. Email parts guy at dealer and here's the biggie. I have to bring the car to the dealer and let a mechanic look at valve and make sure it was installed correctly before they will replace it. They order part and replace it. Needless to say I'm not very happy to take my show winning car to the dealer. I do all my own work and always have. We'll they have a mechanic that has been there since 86 and he has worked on an S38 engine before???? I told them the only way I would do this is if I can be there when he looks at the valve. Here's a photo taken with my bore scope. So just be aware of the potential downfalls of warranty on parts. Can you imagine if this was and expansion valve or rear main seal. We'll see how this ends.