[Hezzy002]

Why don't you just flip the verts along the center of the screen and then translate them down? Also, I'm not sure how you're able to increase performance with the technique you discussed, unless it enables you to render in horizontal strips? But then how would you handle rotation?

It also looks like you have the same problem that everyone else has; if you were to change the viewing angle/view distance to properly look like a SNES racer's horizon, you'll find either horrific artifacts or if you increase the resolution to remedy that, really poor performance.