It goes a bit further than this.
The driver is hard coded into the system. And even if you managed to somehow get it out, it wouldnt do much good because the graphics chipset is propritary (s/p) it wouldnt run just anny vga card....The card or chipset to be exact was designed to run on a tv. and the software was all designed for large fonts / tv display.
So , in short - It wouldnt really work.
Look for good deals on vga stuff.
I found a 8.4 TFT for 40.00, and VGA controller card for 260.00 - not a bad deal.