Sam problem here
I bought my 1998 740il one year ago. When I first noticed water at the interior light dripping I had my BMW shop run a water test. They applied soapy water to the seals and blew compressed air aroung the sunroof and windshield. They deermined I had a windshield leak. I then replaced the windshield (and got took) at a cost of $600. Still leaks but not all the time. I take my car through a carwash and when it is done I also find my floormats getting wet on the front passenger side and my glove box gets about a cup of water in it. I was searching the web when I found your post. I found one site that recommende taking a piece of coax cable and cleaning out the drain ports of the sunfoof. Someone replied to that post that compressed air would also do it and take take the chance of getting the coax stuck. I am going to try to solve this problem this afternoon.
Regarding your rear lights. I had the same problem. One shop which I used to use told me that I needed to replace the rear light housings at a cost of about $800.00! While in another shop (a long story) they changed out the bulb holders, the part you can actually turn and remove to replace the bulb, and I have only had the check brake light come on once. When it did I simply removed the bulb and holder and reinstalled it and no problems. The shop which I use to use, who reccomended th housing changeout no lnger works onmy car. I currently use Dinan Engineering in Mountain View California. I have spent approx. 7K on the car since I bought it so I am in for the long haul. It's good I love driving it and I think it has classic lines which will look good for years to come. This is my 7th BMW.
Let me know if you find anything else out and I will dothe same. Sorry for the long post.
