Here's the one mistake you're making with your petition concept: How many of the people signing this petition will actually be able to afford/buy the new Supra?
Many people seem to forget that the world is in a ditch with the consumption of oil. Cars from here on out need to be running alternative fuels and with the price of this new Supra, only a small percentage of Americans will be able to dish out the money for it. It will become not only a supercar, but a luxury/exotic car.
Now, I'm in love with MKIV Supra's, but I just don't see Toyota producing something that will bring down their sales. It may very well cost them more money to produce than sell. However, IF Toyota decided to produce a certain number and be done after that, they will keep their profits up and most likely sell them all. Just like there were only 7,866 Supra Turbo's produced and exported to the United States between 1993 and 1998. And even less with the Getrag 6-speed transmission.
Sorry to disappoint you all, but if you really want to make a difference, come up with 40 thousand and call Toyota and press them to do it.