Welcome.
Post on the Tech Forum for better results.
Enter your VIN here to find what options the car came with.
http://old.mbclub.ru/mb/vin/?lng=eng
On mine, you have to pull the cup holder past the indent (catch hook) to get to the first aid kit, requires a small jerk.
US cars to my knowledge didnt come with a fire extingisher. Mine certainly didn't.
The kick down switch on the throtle is activated at full throttle only so is probably working correctly. Will down shift 1, 2 or 3 gears depending upon speed/rpm.
Change your trans fluid. It is NOT "filled for life" as was advertised. Use MB fluid for the 722.6 (your model) or 722.9 trans only. NO OTHER.