If you book a convertible with
Alamo/National your odds are GREAT that you will get the 200, OK for the Spyder... and slimmer for the others.
(I am actually surprised the Saab is still in the rotation, that's got to be aging on out there. I drive a Saab and love it, but they haven't made these in a few years sadly and now they are gone forever it looks like

)
I see Mustangs occassionally. Rarely see Saabs and while I have not really check in Orlando I can tell you that in most cities I never see Camaros so I wonder how big the fleet is for that.
(That said having driven all of these.. the Mustang is my least favorite. Worst trunk space, worst blindspots with top up. I thought my Saab had a small trunk until I got a Mustang, my trunk is GIANT by comparison LOL!)