The Sparco Sprint was way too narrow for me.
I like the Cobra Monaco Pro for Miatas, but they are really hard to buy. They're made in England and they only ship a couple of containers of them per year. It's a newer version of the Monaco S that I had in two other Miatas, but the Pro has side mounts. I have a brand new one in my basement, but you can't have it. I ordered it and by the time it arrived, I had sold my car.