I am getting nothing but flying saucers when trees are rendered while driving ground vehicles, making it very hard to navigate and drive. While not a 'major' bug, it makes it very difficult to navigate.
I won't comment on the flashing or most of the other graphical glitches since it is a beta.
Runs ok on my machine, but I have a pretty powerful one.
Dell PIV 2.8
1 gig RAM
GF Ti 4600