Need Radio Antenna Ideas

When I built my '70 Mach One years ago, I replaced both front fenders. The new fenders didn't have provisions for the factory antenna, and I really don't want to drill a hole in the new fender. I'm just using a basic media player/radio in the car, but without the antenna hooked up, local FM barely comes in if at all. We have some good FM stations here, so I'd like to add an antenna of some kind, but would like to keep it....well, subtle if possible.

What are you guys using if you don't have the factory antenna? TIA