Instead of drilling holes in your new car and or spending a lot of money on stealth mobile antennas with questionable performance, why not try this? Buy a MFJ 1721 2 meter magnetic mount antenna and stick it on the roof. The rod is very flexible
will not sustain any damage from being bent over coming in and out of the garage. Performance will be very good for only $12.95
We have used the dual band model on the lady ham's Mustang for years with great
results. It is mounted on a narrow rear deck panel. It is very
low profile and almost impossible to be seen from a distance. You could consider mounting it on the front fender deck of the Mazda, since there is no trunk. Because it is magnetic, you can move it around and try different locations for best performance versus clearance.
As a hint, after you get the antenna, keep in mind that the magnet is very
powerful. Once it sticks you must tilt
the antenna to remove it, which is difficult because of the small base. The magnet is so powerful that you can pull the bottom out of the antenna if you are not careful. I installed a round piece of auto scuff guard tape from Pep Boys on the magnet bottom to cut down on the power and prevent damage to the antenna when removed for washing and drying.
In consideration of your restrictions, for the money and performance wise, this is your best