Is the best video I have seen as to whats happening. He had said he posted it here before but I was not able to find the post. Any help? I have been running NR2K3 at the Daytona 2011 revamp on a regular basis and now it just started glitching like this. I don't wish to reinstall it all. It took an hour to install to first start.
You either have a conflict with your graphics card or a bad graphics card. With it doing that "under load" (race with everything set at max), your card may not be able to handle it. Also check the number of sounds heard in your options setup. Should be no more that 8 max. If your running more that 8 sounds, there is your conflict.