Wish I could find an old Flip flop mount they used to make back in the 70s.... It was hinged and all you would do is open up the trunk and flop out the mount, screw on the antenna and you were good to go. When not in use unscrew the antenna, open the trunk, flop the mount on the inside and you were good to go.

I have a CB that would mount perfect where the ashtray was. Its peaked and tune too, I just don't want a permenent ugly antenna. The magnet mounts ruin paint too, been there done that....