I've had my '84 300D for about a year and have run into a clanking noise coming from somewhere underneath the car, but only after long drives (about 2 hours or so). Other than that it runs great. It seems to clank at a faster rate when I am accelerating.
Does anyone have any thoughts on what the problem is? I know I haven't given much to go on. This is a great site, by the way, it's answered many nagging questions for me (usually i can find my answer using a search). Thanks.