A lot of the time you'll find more info by searching Celica Supra as that's what it was called. I don't know how common they are, but it does seem that support is scarce.
Try the forum here:
http://forums.celicasupra.com/ Search through the classifieds section before posting a "how much is my car worth" thread though... those aren't too well received in a lot of communities; I don't know how the folks over there respond to them.
