JJ, if your car really is as well-maintained and in great shape like you say it is...then it still has a LOT of life left...My car has well over 200k miles, and it is still reliable...I've only had to replace small things, mainly engine components, parts of the TCCS, etc...(mostly just normal wear/maintenance items) but I've found, that after owning a 1-owner 77' Porsche in immaculate condition that the Supra was engineered far better than the porsche, and if subjected to the same abuse that my Supra has been subjected to by it's previous owners, it wouldn't last nearly as long...
So yea, the Supra is a great car that should last a long long time...and I'm not sure if i'll ever buy another older German car. :\