Welcome.......

I've never had any trouble with windows and cannot direct you on that issue, nor can I help you with your speaker issue either, but I can tell you that sun roofs usually don't work, or don't work very well on these 124 cars.

What I can help you with is engine and drive train mechanicals, but you haven't posted any questions regarding such so I can assume all there is well. However, there are several things you should be aware of regarding the 87 300 D.

My advise for you would be to buy a book that was published a few years ago called "Mercedes-Benz E-Class Owner's Bible 1986-1995" you can find this book at any Barnes & Noble, or Boarders, or any book store for about $30 and learn all about the car you own. You will find important things you should be aware of about the 87 300D.

Issues I'm referring to involve the aluminum head used on the OM603 diesel engine powering this car. Also, you can look into the archives here and find a lot of reading about your car. There is a diesel discussion forum here also.