I had a tin of mints hidden in a woollen glove in the rear door pocket that drove me batty for the thick end of 3 weeks (cheers kids!!)totally overlooked as how the hell can a glove rattle and buzz :}
Probably not helpfull but eliminate the obvious by stripping the car bare of all additions and nick knacks
Probably not helpfull but eliminate the obvious by stripping the car bare of all additions and nick knacks