3DTV tips, anyone? Content is 'fat'

I have this nice 55" LG passive TV, and I want to see Unity content in real 3D on it. I can make side-by-side or left-over-right views easy enough with a couple of cameras and setting their viewport params. Let’s say I use side-by-side. My content is now squished horizontally. The TV will take the full screen and interleave as needed to do the 3D.

Here’s the problem: it stretches it horizontally too much. My content looks stretched horizontally. The only way I’ve seen to compensate for this is to make the camera views much narrower, like 50%. Then the aspect is ok, but now I’m only getting half the frame on the TV!
I think what’s happening is the TV wants side-by-side that is twice as wide as the TV.

I think for best results, I would want not a 1920x1080 render, but 3840x1080 (or similar aspect) (or similar solution if stacked vertically).

Is there a way to tell Unity to render double-wide? Or any way I can arrange my cameras to do this? Would using RenderTextures be any help?

The TV also supports ‘checkerboard’ but I’ve never seen the spec on that. And ‘frame sequential’ - I tried swapping cameras every other frame, but the TV won’t go into that mode when the game plays.

Of course I’d much prefer if a driver (like More3D) could step in and handle this for me, so I don’t even have to do two cameras myself.

Actually, swapping cameras in Update (not FixedUpdate) does work with the right graphics card. Sequential mode is available (GeForce 550 ti for example). But be sure to maintain a high frame rate.

My solution was to get the TriDef drivers, set to generic, side-by-side, and just use one camera in my scene (TriDef does the rest). 60 rock-solid FPS, looks good.

Also I think 2 render textures, each proportioned correctly, then seen from a 3rd camera which has them fill the screen, should work ok (if frame rates hold), then can use side-by-side mode.