I've posed this question before, but didn't get any takers. I've got a 2003 Tib. I know the original CD/AM/FM radio is marginal at best. In my particular case, the AM reception is the real bugaboo. What I'm curious about is this: is it the radio, or the antenna? The reason I ask is that I'm thinking of getting an after-market unit, such as a Kenwood. But, I don't want to spend the bucks if the antenna, or its routing, is the real problem. Got any ideas? Many thanks.