I have a 92 300 SE which has the vaccum assist which I just replaced the pump on. It is in the trunk on the left side next to the gas tank. It is very easy to replace. It's cost is about $198.00 US currency rebuilt from George Murphy (email address) [email protected] the door locks and truck handle pump is located under the rear seat on the right side of the car. This one costs about$400.00 US currency from George and is new. Good luck with these issues. I fixed both of mine this past weekend and glad that I did. The door locks and lumbar are on the same pump. Door and truck closers are on the other pump.My 1992 S320 has vacuum door but it doesnt work, Ive tracked a leak down to the lumber bags which Ive fitted new ones (Â£26 each). Does any one know where the resiviour is, as I need to trace the air line back to its sourse. Im sure the other end has come off as well. Does any one have a manual for this car?