1. The comfort open/close function only works via IR, not RF. Therefore, you have to point the remote at the door handle sensor and be within a few feet of it for it to work. Also, make sure the auto-up function on the windows works - if they have become desynchronized, such as what happens if the vehicle battery has been disconnected - the comfort open/close won't work. Finally, the IR sensors in the door handle degrades over time so it's possible this functionality might not work reliably.
2. The power fold mirrors is an option. If your vehicle has it, there will be a button for it on the panel where the headlight switch is located.
3. C/S adjust the transmission shift patterns. C = Comfort and it will cause the transmission to start in 2nd gear (helping to avoid wheelspin on slick surfaces) and it will upshift sooner and downshift later. S = Sport, meaning it will start in 1st gear, hold gears longer, and downshift more quickly.
It sounds like you need an owner's manual. You can download one here:
W203 2003 Owner's Manual
