So my 1991 MR2 GT's boot wont open with the key.
The little handle in the car works (You can hear the cable moving), but the boot doesn't actually pop.
Anyone know how to get in their and fix it?

I don't know if this may help, but on my car the cable pull will not work if you have turned the key in the lock counterclockwise. I think that's the way it is designed.
I found that it often got stuck in the counterclockwise position,  and I had to twist and shake the key to get it to open (but not too hard of course)
 

If the lever and the key both dont work its probably dislodged from the boot latch. Time for a locksmith