Mercedes car seats have very little lumbar support. This eHow will show an inexpensive way to add lumbar support. Example shown below is a '99 SLK but will apply to other models.
After purchasing lumbar foam, test it on a seat and shave to appropriate thickness for your back. The foam shop will cut the foam down for you usually without any charge. It can also be cut by using an electric knife.
The seat leather cover is remove by simply pulling away to the retaining fold along the back of the chair. No tools necessary.
At the back bottom of the seat, there is a plastic retainer that needs to be pulled away. No tool necessary.
The seat cover can now be pulled away from the seat back. There are a few plastic clips that will need to be removed.
At the center of the seat, there is a fabric tie down that will need to be cut by using a knife. This will make room for the foam to be inserted.
Reattach the clips and the seat cover. All done! The seat is now pregnant! :) This picture shows original foam support before it was shaved 2" to reduce the thickness.
