I just used MB part number 000 989 36 60 (small bottle of liquid) on my girlfriend's 1999 SLK, by applying it with a terry towel and waiting around 15-20 min, and then wiping off the excess. I did all the rubber seals for the top, pillars, even the door and trunk rubber. Works best when leaving the car running and then opening the top half way up. (In around 10 minutes there's a timer that wants to lower the top again, and the beeper goes off to warn that this is happening, but then you can just open it back up again if not done with the application).
We just took a test drive with the top up, over a very bumpy road where it normally used to squeak like heck, and now it's as silent as when the car was new. The stuff really did the trick, and made the rubber much more pliable and silent.
I get the stuff cheaper being an MBUSA employee, but I think list price is around $42.50. Kind of expensive, but it sure works. The consistency of the liquid is a bit like glycerin. Used just a little more than half the bottle, and was generous in the use, so it should be good for two total applications. I think this is the first time this has been done on this car in 10 years. Probably will last for some time I think.

Mike

 

Well done.

Search for Krytox . It is same stuff and can be found on Ebay etc as well.

Bazzle