The problem with a Miata is that it's a 2 seat sports car and I know a little something about 2 seat sports cars cause I've owned 3 of them. You are very room challenged for starters if there are two of you. I've also owned 2 Mustangs and two people can travel with far more room than a Miata. 

Another benefit is the sheer passing power of a Mustang (or Camaro). If I need to pull out and pass I have 400+ HP in which to accomplish the feat and can do it in a big hurry which comes in handy on BC highways. I still own a 2 seater but am seriously thinking of getting rid of it for the above reasons, especially the room part.