You'll be happy to hear that there's a huge variety of both luxury and economy rentals in Southwest. What you end up going for depends on what you're willing to spend and what you're hoping to do. Specialty vehicles are hard to beat if you're all about mod cons and comfort. If you feel like splashing out, why not book an elite SUV, or perhaps a slick mid-sized vehicle? Alternatively, if you just need something to whiz around town in as cheaply as possible, maybe go for an economy vehicle (or something else that won't burn a hole in your wallet).