84300dt...thats exactly where the drains lead to. I remember when my 300 sd began having all kinds of leaks in both the trunk and interior I almost went crazy trying to figure it out. Luckily my old mechanic down miami (who is an absolute saint when it comes to reliability, honesty, and being able to offer sincere advice) showed me that i could pour water down the little sunroof track and if everything was working right it would leak out through the bottom of the rear rocker panels. It actually has a drain for the front end too. He told me another common problem that could lead to leaks in the same area is rust developing in those drainage lines or on the actual sunroof shaft itself. Funny about the icicles though, thank god i dont live anywhere that cold.