Owner of a '95 Miata (roughly 81k miles, original top) here:
Definitely check out miata.net, as mentioned up-thread. You’ll find there all kinds of great information: common annoyances and how to fix them, easy and/or cheap ways to fix stuff, advice on tires, etc.
Some specific tips I’ll mention:
The car is very light: tires will make or break your driving experience. Go for lightweight ones and make sure they’re well balanced and are equally inflated. I had two tires (front passenger, driver rear) that I had to have patched due to punctures, and neglected to bleed off the extra air: when I hit about 50 mph I could really feel that 8-10 psi difference!
Top maintenance: if you have a plastic window and it gets scratched/hazy, visit your local boating repair place and pick up the stuff they use on plastic boating windows to clean those up. Works like a charm. Also the marine grade goop/glue stuff (UV resistant, dries flexible, available in many colors) is great for fixing up an older top.
When putting the top down, have something soft like a towel to put under and over the window. Helps keep it from getting scratched.
Don’t have a hard top but want one? There’s a place that is making carbon fiber hard tops for the Miata: unfortunately I’m not at my usual computer at the moment else I’d dig up the link for you. If/when I pick up a hard top, it’ll probably be a carbon fiber one if only because of the weight savings.
Be sure to test drive the car for a decent distance: I have no problems with the proportions of the car, but my father can’t find a good place to put his right leg. I could probably drive that car cross-country with no problems, but my poor Dad’s leg would be cramping even before he left town.
And lastly, I must admit to smiling inside when I fill up at the gas station. Nothing like watching the person filling up their SUV/large pickup/van keep glancing over to my total.
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