I recently used Krytox GPL 205 Grease on a squeaking seat. It worked fantastic. My understanding is that its the same as the Mercedes Sliding Compound without the Mercedes markup. 1/2 oz was $19 on Amazon. On my 2018 C63s my driver’s seatbelt rubbed against the AMG performance seat at my left shoulder. It was a very annoying non stop squeaking/creaking that was only made louder as it was close to my ear. Any slight movement in the seat created the sound. I tried silicone grease but it didn’t go completely away and only lasted for a couple days. So far with Krytox two weeks and no sound. Its expensive but a little goes a long way. I may have brought on this sound myself as it began after treating the seat with leather conditioner. I used nitrile gloves as the grease is toxic.

 

This stuff is magic. BTW gloves as a must as it can't be removed with soaps / degreasers!

 

Shame I cant get it shipped to AUS