IIRC when I did mine the car side of the ISO plug (The two standardised plugs one black, one grey) had some wires which were the wrong way around such as the switched and constant power. You might have to just make sure they are connected right using either a multimeter or similar (obviously make the changes on your adapter just in case you go back to a stock head unit). As for reception, Make sure that your head unit takes a boosted signal. I recently downgraded to a r32 head unit and was having awful reception issues. Came down to having the boosted antenna hooked up when the stock r32 doesn't have boosted antenna but the bora did.