I wasn't familiar with the eX-Driver series, but that's not a prerequisite when watching this film. The concept is simple enough and you won't have much trouble catching on, though I'm pretty certain I missed out on some of the finer nuances. That said, the drama isn't really the film's strong point.
eX-Driver is built around the action/race scenes. At times, it felt like a tech demo for the cel shaded racing sequences, which don't look that bad considering the film's age. It's not exactly seamless, but the effect is already there and the races themselves can be quite thrilling.
The rest of the film is just filler. The art style is bland, the animation is simplistic and the plot is just dull. Luckily the film is short, meaning the time between races passes quickly and is easy enough to bridge. As a bit of mindless filler eX-Driver isn't the worst, but I wouldn't recommend it otherwise.