To improve the seat comfort issue, today I had seats from an SLK 230 installed. They went in fine, electric and heated seat connections and all. These SLK seats are noticeably more comfortable. The upper seatback bolsters behind your shoulders are about 2" shallower than the stock seat, and this allows you to sit with your shoulders farther back and not pushed forward.


Also, since the SLK has a removable rather than integrated headrest, the seat back reclines further, adding more comfort.


I post this since over the last couple years on the forum I've noticed a few other posts about seat comfort.
Hope this helps anyone with a similar concern.