Hi Guys, The front bottom Passenger side door speaker is crackling when I turn up the volume and it's very annoying, it was like that when I bought the car last year but it’ got worse... I got a quote from MB for £140 Inc fitting, the part is £70.20 which is the H/K, I’ve already paid for the part. They quoted me for more on hour labour? I would have thought it's a 30mins job? Any ideas? Thanks.