Can you give a little more info than "can't get it to work"? Does it power up? Does it just not start the car? Do any sensors react / respond?
Can you make as detailed a list as possible of what does work, what doesn't work, what may work but you're not sure, etc...?
Can you also describe your wiring / installation as detailed as possible?
What testing have you done, have you tested for power, tested for ground, tested for why it's not doing what it's not doing?
I can probably help you a bit faster if you shoot me an email to firstname.lastname@example.org Just put something in the email about MR2 / 4AG / etc.. and I'll find it