Thanks so much for everyone's help. After calling Pep Boys, Autozone and O'Reilly, no one carried any strips of leather or vinyl. Autozone had a seat repair kit, but I was a bit uneasy about sealing space-age Miata roof up myself. I called an upholstery shop here in Arlington. Initially the guys estimated $1200 and tried to replace the whole thing, but after further negotiations, they agreed to sew a patch on that will keep the rain out for $75. They said they'll even use the same material the top's made of! Now to get that dent fixed...
You guys can have it; a tan roof with my car's interior would look silly.
How did you guess? Technically it was the "non-economy" lot right next to it. Needless to say I won't be parking at 1901 Main St anymore. Instead there's a garage caddy corner to it that costs less... provided I get my parking validated in the school's office.
There's something weird here. We're both students living in Arlington who were born in May of '83 and have had recent bad luck with our cars.