Are you comfortable driving a little car in which you can get squashed like a grape by a larger vehicle that may or may not know it has even hit anything?
If so, go for the Miata.
I can tell you that our regular cars are about the size of your Park Avenue and when I get in the Solstice I feel very vulnerable to larger vehicles on the road, most of whom are driven by idiot maniacs who should not be allowed to be in control of a can opener.
We have less than 1K since new on our Sol, and it will not get more than 10K on it in our lifetime, if that tells you anything.
edit: Never had a Miata, but here are the pros and cons of small cars:
pro: they are small, so they are a hoot to drive and they are cute to look at it particularly if you have a good looking wife sitting in it, and they don't take up a lot of room in the garage, shop, whatever you store them in when they are not being driven, which is 99% of the time you own it.
con: they are small, pretty much anything on the road can kill you in it, can't carry much of anything, making them a day trip / weekend trip car. They are a lot of fun for this, so maybe that it is a pro after all.