I have a 2003 slk 200, the roof creaks over anything but a perfectly smooth surface, would it help reduce this by lubricating the rubbers,if so what would you recommend using ?

 

try WURTH silicon spray.

 

or better still MAguires rubber trim conditioner or 303.

MB, Volkswagen and others sell a small tube of seal lube at about $90 ... hmmm

If you use silicone beaware that some rubbers can swell with some brands.

Bazzle