I kept trying, i am have finally found a way to enable Ambient Occlusion via Nvidia Inspector.
You gotta use the "Ambient Occlusion compatility" mode "Fallout 3" and turn Ambient Occlusion setting to "High Quality" and the Ambient Occlusion usage to "Enabled".
I have even played around with Anisotropic Filtering x16 (for improved texture quality) and 8x Spare Grid Super Antialiasing, Texture filtering - LOD Bias -1.5 (for stuff like vegetation, fences, ...) and got some satisfying results, although the differences are subtle.
I gonna provide a few comparison screenshots (raw = BF2 high settings without above mentioned), maybe i gonna write a short tutorial about this:
https://dl.dropbox.com/u/106806270/Ambi ... lusion.zip
Preview:
RAW:

AO Quality:

RAW:

AO Quality:

RAW:

AO Quality:



WARNING: This will have a impact on your frame rate. I have turned down the AO to "Qualty" instead of "High Quality". Gives a better frame rate and looks a bit more realistic. "High Quality" is a bit too much shadow drawing.
EDIT:
I moved to just Super Sampling Antialiasing x8 for "Transparency AA", which looks way better when moving around instead of on stationary screenshots. And i even got some decent fps improvements with just "Quality" instead of "High Quality" as stated above. Right now, the the fps decrease isn't just as significant as before, but i still get a way better graphics result than with "default high settings".








