"4) the front right headlight is out, and i was wondering what xenon/halogen brands work good with mb, keeping in mind, cost is a big factor for a 16 year old."

There is some chance that the socket has melted. Do not put high wattage lights in with stock wiring.

"3) The sunroof doesnt work, im guessing the motor is broken, and i would like to know how to replace it, if its not too costly"

Start with the fuse and the switch.

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1986 300E 5-Speed 240k mi.