Great pickup
someone loved that car at some point (in their own special way)
remember, this car is almost 30 years old so there will be problems. but if the major components are in good shape (engine, Transmission, cooling system, electrical) then you made an awesome purchase !
The antenna doesn't go up or down - check the fuses first
It does have a aftermarket radio- I wonder if they wired the antenna into the aftermarket stereo
-- i will have to check into it more. Ive noticed when they installed it they didnt bypass the fader knob in center console.
The rear headrests don't retract- check your fuses first , otherwise, it could be the switch
-- will do.
Its got a small coolant leak on passenger side by reservoir. Looks like some sort of valve- is it leaking or is it from expansion (as someone previously posted)
And also i believe it is a little low on coolant fill it up but don't overfill, otherwise it will be released and you will think its leaking.
At idle heater is not as hot but if revved to 2k it is again- I wonder if the heater core is working as it should ?
-- i think its just air bubbles as i get a gurgling at about 3k rpm.
Here is a good link from a sister site concerning the car
Mercedes Benz Model 124 - M103 Maintenance Manuals