Mister2 this is a forum, 260z simply wanted others opinions and we as human beings are each entitled to our own. We all have something valuable to share :)

OK. Here's what the biggest tyre seller in the U.S. (and probably the whole world) has to say. I'll leave you to judge if this is just "uneducated opinion".
 
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=136
 
 

I have used different tyres front to rear many times including on the track and it is absolutely fine.
If you have a direct drive 4x4 like an earlier WRX or GT4 Celica you do need to make sure the circumference is the same though. For an MR2, that won't be a problem.
The same rules still apply to buying tyres - even when you are buying the same for all four corners. i.e. you get what you pay for. The only thing I look for these days is treadwear rating. The lower the number, the more grip you get.
I have Federal 595 RSR's on my GT4 at the moment and they have a 150 rating. I previously had Dunlop Sport Maxx and they were 220 or so. If you want proper performance, don't go higher than 250. As a comparison, semi-slicks are usually between 30 and 50.
If a manufacturer doesn't state treadwear rating, I don't buy them.
So.... to cut a long story short. It's OK to have mismatched tyres front to rear as long as the treadwear rating is similar.
NEVER mismatch tyres between left and right!