Love that game... do you play it on PC?

That fan will work for circulation. It will basically blow the hot air around inside. You need a fan to exhaust the hot air buildup inside the cab.

A good idea would be to cut a passive intake hole near the bottom of the cab and an exhaust hole near the top where the hot air rises. Attach some cheap ducting to the exhaust and have an inline fan pulling the hot air out. You can also DIY a carbon filter to fit with the fan for odor control.

this is just an example of the type of fan im talking about...
ECO PLUS 4 INCH 17 CFM INLINE FAN HYDROPONICS COOLING - eBay (item 400000999871 end time Mar-26-10 07:37:02 PDT)

Its best to buy a fan that sucks more air than you need and use a fan controller to bring the RPM down to match it to your cab. The only bad thing about those fans are the price. They are well worth it and you will be able to use it with a DIY cab or tent or a small closet.