Hi, just put in a Panasonic Hu myself into mk2b punto, on mine & it should be the same RED/WHITE wire on the car wiring is permanent live,BLACK wire is earth, you should have a standard ISO adaptor which plugs into the car plug & then into the Hu they should match up without moving connections as on mine YELLOW wire connection to RED/WHITE on car, BLACK wire to BLACK wire on car, if you do need to move them, move the spade connections on the adaptor lead to match the car plug this is done by using a paperclip or piece of thin wire which can be pushed into the back of the plug to release connection which you can move to the correct position. Any probs let me know.
