One problem which occurs is in terms of the aerial cable connection to the back of the head unit. On my wagon the wire to the centre pin of the connector had broken, meaning poor & patchy radio reception. The solution was just to run a replacement cabel from the aerial to the head unit, and whhen I did this, becuase I'd fitted a JVC stereo, I also just fitted a cable with a standard (is it ISO?) plug on the end, rather than the jap spec cable which in turn needed an adaptor to fit the JVC. Only cost a few quid from Halfords, the radio reception was fine after this.