Actually, MB uses natural rubber compounds farmed from rubber trees instead of synthethic junk..... its higher quality, oil and heat resistant.

Most of the major components - engine mounts, suspension bushings should be on everybody's list of items to retorque at least each couple of years.... so they dont get lose and shake themselves to bits.

Still, a very good question - Is there rubber lube product that can prevent drying out of window seals, etc??