'68 Barracuda Notch

I sold my house and I won't be near my body guy after I move, so I'm considering biting the bullet and painting the rest of the car.

I have a couple body mods in mind that I want some opinions on. The first is the exhaust cutouts in the rear fascia. I only have one and it doesn't line up with my exhaust tip at all. I have dual exhaust and both tips just exit under the fascia. Should I fill in the existing cutout, add a second cutout and rear do my exhaust or something different? Here are the best pictures I have at the moment.





The second body mod is the antenna hole. I don't even have an antenna right now (much less a radio), but I do like listening to FM radio. If I fill in this hole, are hidden antennas reliable enough to use?