I just bought this car anthe radio didn't work when I got it an it has an aftermarket stereo but I just thought that maybe the plug wiggled it's way out but it turns out that I can't find the antenna for it at all. Anyone got ideas as to what happened? I can't even find a spot that looks like there was one

 

Looking strange because factory Golf had a radio that runs with the help of antenna and you were described that there is even no spot. I think you should concerned your older owner regarding this problem.