This guy over at reddit installed a bunch of realism mods on the PC version and packed them so you can get them too.
http://www.reddit.com/r/truegaming/c..._gritty_grand/
It's f**king incredible.

The high damage, realistic gun sounds and police actually stopping you if you violate traffic laws or walk around with a gun make the whole game crazy. The chases are way more intense too coz cars take more damage and most pedestrians lock their car doors, so when you wreck a car it's nerve-wracking to find another set of wheels when you can get gunned down in 3 hits.