There's a fine line between supporting the ministry of a radio station by advertising there and (my opinion) shamelessly tagging themselves "your Christian chiropractor" for example. WMUZ appears to have a high threshold of tolerance when accepting $$$ for ads. They have commercials for attorneys who will defend parents of children with birth defects. Not that some cases don't warrant attention, but IMO they are playing to the emotions of people in a very vulnerable place, having just lost a child or given birth to one with a defect. That kind of advertising has no place on a Christian station, IMHO.
Getting back to topic...
StrangeLove, here again, you're digging your heals in, and I have no idea what you hope to achieve. A few of us are comforted when we see a fellow Christian on the road, and you would have no other way of knowing if they didn't have some sort of symbol. It's my understanding that early Christians would draw the symbol in the sand to privately indicate to another person what they were a Believer. Was this idolatry to you? Should they have refrained from this practice that communicated their relationship with the other person?