$75 to re-enter the radio code?!?
Mercedes Benz always did it for free.
I used to work for a technician who had started out as a diesel bus mechanic but had acquired a following of loyal following of Mercedes diesel owners so he started his own business. He could fix anything on an OM617 but couldn't code the radio back in so I would have to take the short drive to the Mercedes Benz dealer and get them to reset it.
Deal with very nice service writer who passes car off to smug assistant. Sit in waiting room and have a complimentary coffee for 15 or 20 minutes and I was back on my way to work. No charge.
Except for the smug valet/assistant, nice people and good coffee. A pleasant experience.
As far as changing the headlight bulb? You can do it from underhood on a Mazda6. Your hand will look like you got into a fight with a rabid feral cat and you have to set the locking clip down blind but it can be done. It's actually easier to remove the front bumper cover and headlight assembly and install the light on the work bench.