Slider - I dont know much about un-even tire wear being a problem. Im on a mr2 forum as well, and have been for the last 2 years and i have never in my life heard of un-even tire wear being a problem. And open diff might contribute to it, but thats about it, theres no real problem. MOST-all 93+ came with LSD.
The improvement you are talking about is the suspension, and this was improved in 1993. 91-92 mr2s had a problem with snap-oversteer. And in 93, toyota re-did the suspension to have it be more predictable, and grip a little more. Its also 1" lower than the 91/92's due to all this. The transmission was also re-done, because the 91/92's had weak syncros, the 93's transmission shifts like fluid, and has VERY short throw. (shorter than my 91 w/ short shifter installed. ) The taillights were updated in 1994.
So yeah, this particular mr2 does have the upgraded suspension to correct most of the oversteer you all have been mentioning. I, as many others, have had my horrible run-ins with oversteer.
It was late one night, i was driving on a empty road next to cow pastures, pushing it faster than i should. The road was still damp from an early night rain. So there i was, flying around a corner, and boom...it happend. The rear started to slip a TINY bit, and i hit the brakes a little bit, and the rear snapped out faster than anything you could imagine. All of a sudden the i was sliding backwards, and the car started spinning. The flew off the road at over 100 mph, into a ditch, which launched me through a barb-wire fence, and into a cow pasture, destroying my two thousand dollar paint job, and perfect stock-bodies mr2. I hate what happend, and i take full respondsibility. I never do anything like that anymore. Dont get me wrong though, this was at 2 in the mornign, no cars/ traffic/ racing what ever. A open road, with a minor bend, only surrounded by cow pastures for miles in the middle of no-where.
I didnt file a report, so i had no help from insurance. I spent the next 5-6 months fixing it myself, in my driveway, out of my pocket (had to get a loan as well). THats why theres a body kit on it now, i installed that myself, as it was cheaper than all new oem bumpers. There wasnt any mechanical damage, only a ton of bodywork, and a couple flat tires. Here are some pics:(56k warning)
Before:
http://www.eniety.com/pichost/pic/DCP_0043.JPG
After:
http://www.eniety.com/pichost/pic/mr2crash2.jpg
Another 5-6 months...
http://www.eniety.com/pichost/pic/DCP_0018.JPG
Now!! w00t (800 dollar macco paint job, all i could afford, but came out pretty good as i am good terms with the manager. Full wet sand and buff, lifetime warrenty, and good job.)
http://www.eniety.com/pichost/pic/d44.jpg