I took the time to experiment with eyefinity gaming on 3 Zalman 22" passive monitors (sadly I don't own 3, but used it plus a couple of non 3d monitors to fill the set) and setup a 3x 1680x1050 eyefinity group.
I used iz3d's driver set to interlaced and took Dirt3 out for a spin trying the zalman on different parts of the group, and the 3d works across the whole set as expected. (Of course I had to put up with interlaced double vision on my non stereo monitors).
also at
http://imgur.com/a/hdUAn