you can access the cable adjuster (on my 300E anyway) without having to remove the air cleaner assembly. If I remember rightly, you move the adjuster towards the firewall for higher rev's before it shifts, and opposite for faster lower rev shifts. I set mine so the transmission shifts at around 2000 to 3000 rpm with 'normal' pressure on the gas pedal. This translated to 2 1/2 turns I think. Before it would shift up through the gears quite fast, making acceleration quite sluggish.
I also made a mark on the adjuster and cable and counted the number of turns I made, just in-case I screwed it up
