Re: Miata MX5 1991
http://forum.miata.net/vb/ The best Miata resource out there (IMHO). They are a forum and also have a faq section, used buyers checklist, common problem list, how to's, ect., ect...
I don't know much about earlier models but my 99 has been a great car!!! Fun to drive, reliable, cheep maintenance items.
The gas mileage isn't what you would expect from a compact car, but fun cheep transportation non-the less.
There is a huge aftermarket for them (from suspension, turbo's, exterior items, ect).