Gamertell takes a hands-on look at DIPRIP, a Half Life 2 mod. From the article:
"Half Life 2 mod DIPRIP is car combat with your mouse and keyboard. Let's break that down for a second: It's a Half-Life 2 mod, so it should have all the rendering and physics power of the Freeman adventure, and it's on mouse and keyboard, so it should have all the pinpoint accuracy and diverse weapon sets that PC shooting embodies.
Those benefits are in there somewhere, but you have to work a bit to enjoy them...
It's a promising proposition with a few technical holdups. DIPRIP is probably worth an afternoon. It's free, anyway."