Hi fellas.
Once again, thank you for all your suggestions. A new auto radio shop has opened not too far from me, so I'm soon going to print this thread and take it there and see which ideas they recommend.
I will keep the idea in mind of using my phone to pick up AM broadcasts, but again, I'd like to use the BRZ's radio for range and clarity reasons.
So thanks again, and once I talk to them I'll let you know what they say.