Watch out for tie down interference. That's why I moved my pitot a little further out than the plans. I know I spend quite a bit of time under the wing checking the air in the mains, I can't recall the distance between the two panels if that would become problematic either.
I've never seen antenna under the wings, but that doesn't mean it can't be done.
Mine are under each of the rear seats. I made an access panel in the seat pan to get to them if needed. I've not had any issues with that location in four years of flying.