Audio Systems: Horrible radio reception - 2004 BMW 325Ci, 2004 bmw 325ci, bmw dealer network

Question
A while back radio reception in my wife's 2004 BMW 325Ci became absolutely horrible.  Someone told her the antenna was in the rear window, and that the window should be replaced.  The only "grid" I've noticed in the rear window glass is the defogger. The car is a very basic 325Ci with the standard AM/FM/single CD radio and NO "shark fin" antenna - no antenna visible at all.

I've seen mention on the Internet of an antenna amplifier in these cars, supposedly concealed in the "C" pillar, but I can't seem to find any further info.

QUESTIONS: Does the 2004 325Ci have an antenna amplifier?  If so, how does one get to it and how can you tell if it needs to be replaced?  Hopefully it's not a dealer-only part.

Thanks,

Jim

Answer
It has an antenna preamp and it looks like this:

http://cgi.ebay.com/ebaymotors/BMW-E46-325CI-ANTENNA-FM-RADIO-AMPLIFIER-OEM-AMP-...

It is likely to be either the cables connecting to and from including the dc voltage feed OR the amplifier itself.

There may be others on eBay or craigslist or such.  If you order it up through the BMW dealer network you will likely have to pay $$$$ for it!

As to the antenna, it could very well be the defogger wires that are used for the antenna; if so, there is usually a little coupling connector where the 12v line feeds the heating wires.  There is a little rf matching coil inside the coupling link to it.  Sometimes a window shop can repair where the window wire has broken off the connection.

That is my best guesstimation without seeing the car;  we work blind here at allexperts.com as you know!  Maybe some day we can use real-time video feeds.