Well, there are a couple things to consider.
A. Do you listen to AM radio? If so, you may lose some of your reception.
B. There's a good chance your hood may not be painted under it. Not sure how the finish is on the 06 mustangs, but I know pre-05 many color cars didn't get the under side of the hood painted due to the insulation.
I've had mine off for 8 years now. It is unpainted, but I plan to paint it when I repaint the car. I live in Louisiana
...scorching summers, stop and go traffic....I have zero issues with paint bubbling in case anyone tries to tell you the paint will bubble.
"When I know more, I'll be forthcoming. Or I won't be forthcoming, and I'll be honestly deceptive." - Les Miles