Well, logic has finally stepped in and it looks like the Miata is not really a good idea. Premium gas, 30 mpg, relatively high insurance, plus a car payment adds up to quite an unneeded financial mess. Especially that last part.
I could snag a DD Saturn (the default because I have so much experience with them) for $1-3k that would last years with very little maintenance and return ~33 combined on regular gas. But it wont have any damn character.
Knowing that I can't leave any car alone ever, I would probably end up modifying it. My guess would be 17x7.5 wheels, coil-overs, widened rear track, etc. Basically a slammed wagon that still handles pretty well. I'd probably use it as a development platform for several aftermarket components (anything I can't put on the autox car due to STS rules) such as longer lateral links, hub spacers, etc. Also, because it wont conform to any autox rules, it allows me to experiment with different engine options: A low boost turbo setup for fuel economy, a built NA motor using stock components, etc.
But something tells me that's not enough character. Its still a plastic station wagon with a stiff suspension, sticky tires, and maybe a some more power. Somehow today the idea of the old slant six popped back into my head. A slant powered car (Aspen, Volare, Valiant, Dart, Duster, etc) can be had for around $1500 in running condition. This engine has next to zero aftermarket support, weighs like 9 tons and makes around 7 horsepower. It has character. I was tossing around the idea of a custom manifold for a bigger car and a blow through turbo setup, or maybe even a full EFI setup. A 70s chrysler costs nothing to insure. It has no emissions regulations. 25mpg highway is about what I'm looking at with a stock motor in good tune. At 12k miles a year I figure the difference in cost is actually minimal, unless gas prices skyrocket (even more). The downside is, even once the engine is built, it takes a lot of work to this chassis to make it handle whatsoever (coming from an STS autocrosser), and there is the problem of rust - even with a VA car.
I'm hoping that this idea passes. I have a ton of projects as it is. But I have always wanted to do a turbo/efi slant. Now I have the tools and financial means to do so. Somebody talk me out of this.