Hi, yes that what i was thinking, but looking at the back of the audio unit, it is 2 ISO blocks and one other block, that dont seem to be tampered with, one thing though i have now found that the previous owner had a telephone kit in it, and following the wires down it looks like they may have cut the cables to fit it, i am going to have to wait till next weekend so i can pull out the wiring adn see what has been done, i dont suppose you know where i can get a wiring diagram?