I'm brand spankin new here. This is my 4th Z4 and i'm trying to fix the premium/hifi carver amp issue. My car is an early production of 03/03. I found a used premium/hifi amp that's a factory part# but doesn't say Carver. Does anyone here know a way to check compatibility before i buy it? Thanks in advance the part# of the replacement radio i found is 65. 126974231 My vin# is 4USBT33493LR63721