Hi all, i know some of you were wondering about this not too long ago and here's the answer: They fit! Me and a buddy just put my old wrx wagon seats into his 91 legacy wagon. The rear pretty much slips right in using the wrx brakects on the sides. You have to use the lower mount holea(on the braket) on the upper hole in the car to make the lacthes line up properly. With that you would have to figure out something for the extra bolt or just leave it alone. The bottom cushion goes in and the bolt loops line up perfectly! The only problem is on the wrx there is a center braket on the back of the seat that there isn't on the legacy. So you would either have to cut this off or drill very very carefully through and put some bolts in through one of the gas tank access holes.
There is some gap on the back seats between the outter seat cushions and the side of the door area. But not bad at all.
Front seats go right in. Have to change over the seat belt clickers of course. Set in some what higher than stock but not unbarable.
I'll have some pics up on my yahoo pic page soon.