Radio problems

Hello and Frohes Fest dear motor talkers!! Have an interesting problem which I can not get myself.. And indeed my girlfriend got a new radio and I bought her new boxes. When I wanted to install these I almost fell over over. Ugble patching mess from the previous owner, on the driver side was the original plastic holder with plug still on, possibly also the original box (bosch or something), on the passenger side was installed a magnat box, but like! Of the original plastic holders was to be seen nix, the thing was with such a kind of aluminum tube distance pieces and rusty screws at the door fixed. Also from the original plug was to be seen. Well, I first had the new boxes reasonably properly attached. Now to the actual problem: wanted to install the new radio today but already the car (with the original VW alpha radio) to our garage was cracked it by the original radio and wonderful as soon as I heard the sound of the radio. But there was no new radio again.