If you run BRINK with three monitors, the HUD will be placed on the very left and right sides of the outer two monitors. It should center the HUD to the monitor in the middle. Can we get either a cvar to re-position the HUD or perhaps some kind of automatic detection and centering?

On a related note, to get an unstretched game with three monitors, you'll need to edit your config file to include:
seta r_mode "-1"
seta r_customWidth "5760"
seta r_customHeight "1200"
seta r_aspectRatio "-1"
seta r_customAspectRatioH "24"
seta r_customAspectRatioV "5"

I guess the developers could look at the game resolution, apply conventional monitor designs to it (16:9, 16:10, etc) and figure out when you're in a multi-monitor situation, and either adjust the HUD accordingly or allow you to choose HUD location.