Got it working, though it's still stretched. It's squished from the top and bottom, not the two sides, so the thing didn't help much. Just allowed me to see more, but the circles are still ovals. I was hoping for something that would put some black bars on the side so the screen is square. I somehow got BF2 to open in a window where it was perfectly square and straight, but it was a bit too small.
Widescreen Fixer changes the FOV so that it's not zoomed in when using a widescreen resolution. It does not prevent the HUD from stretching at all. With +widescreen 1, the game will display widescreen resolutions, but the HUD is still stretched even there.
If you want black bars, and you have a nVidia card, set the game to a 4:3 resolution, and then in the nVidia control panel set the monitor scaling to fixed-aspect ratio.
You can create a custom resolution if you want the 4:3 res to take up the whole vertical part without scaling vertically.