Ditch the precats if you haven't already, and don't believe anyone who tells you that you don't need to on FL cars: I wrote the book* on that subject, and you'll see my Sticky on both the OC and ROC (and some other places who have pinched it, too!).
Tyre sizes & pressures are pretty critical on the MR2, more so than anything else other than an Elise, so check they're right. If you do no other mods at all, get yourself a front strut brace as it absolutely transforms the handling.
*Well, not a book, more a page on an internet forum. Close enough though!