ok now i have found since owning mk4's i have found disconnecting the battery can solve lots of problems like my high idle issues and my stereo! i couldnt have the bass up full as it was all distorted etc, once i removed th battery for an hour or so to do some work on it i have now found the stereo is all good, my idle probs sorted and my alarm now bleeps when locking, can anyone explain what disconnecting the battery actually does?!