Adding an Alarm to a '74 240D
 

Seeing as how theft and general malfeasance is a concern in my neighborhood, I feel obliged to install some kind of alarm in my recently acquired W115 240D. I'm not at all concerned about the car itself being stolen, mainly just having the windows busted out and the stereo and speakers removed. Or just generally having the car messed with by the unsavory types that like to loiter in the alley. (I have had all manner of meaningless and worthless doodads stolen from my soft-topped Jeep, simply because they could be.)

I'm thinking maybe a proximity alarm to give a few chirps to a would-be a*****e to hopefully deter him. Or if nothing else, a loud alarm to wake me up in time to get down there and hopefully throw some lead his way.

So my question is: are there any special concerns with installing an alarm on a vintage car such as this? I would normally just take it to the alarm/stereo dude down the street, but I wasn't sure (having never owned an older car) if maybe there were certain considerations that your average alarm/stereo dude wouldn't know. Would hate to have him muck around in side the doors or under the hood and mess some thing up.

Your thoughts are appreciated. Thanks!