I've already solved this on my PC which is just a tiny bit above the minimum requirements (a 9800GT instead of the 8800 that the "minimum" list showed).
Here's my: "How to Solve the RAGE Texture Streaming Pop-in Bug" tweak guide: http://imbacore.blogspot.co...
If my low-end PC can run the game smoothly, I'm sure you ...
Here's what I did to solve RAGE texture problems:
http://imbacore.blogspot.co...
The guide can be applied to both AMD and Nvidia cards.