I think you're out of luck on this one. That's just how it works.
I got an in-dash xenarc 7" touchscreen for a cleaner install than the standalone I had been trying to balance on the dash. So now I have an extra screen that I want to use outside of my car, like on my desktop G5.
The problem is that the egalax driver assumes that the touchscreen is the primary display (ie. the one with the menu bar) in not-mirrored mode. When I leave the menubar on my 23" screen and use the touchscreen, the mouse actions happen on the big screen, rather than on the buttons or whatever that i'm trying to touch on the small screen.
If I move the menubar to the xenarc, everything works properly. When I touch things on the xenarc, the actions happen on what I touch. But I don't like this setup because the menubar is extremely limited by the 800px width, and some apps (ahem... Firefox...) open new windows that are only 480px high, even though the screen it opens on has 1200 height.
Anyone know a fix to let the egalax driver translate its coordinates to the 2nd display?