Richard,
Whenever I'd shoot road test video, I'd set up for what I called the "shark shot."
1. Position camera-man in back of the pickup or minivan that's in front of the test (subject) car. Shoot out of the tailgate, looking directly back. It's tough to get non-shaky video with just a camera mount, but if you practice you can do it with a mount and a gyro. Easier to have a camera person, though.
2. Have the camera vehicle drive a consistent speed, on a straight road.
3. Have the subject car (the one chasing the camera car) quickly speed up to within a few feet of the rear bumper, than fade back, then charge up again, veering slightly side to side as if it's a shark chasing a fast bill-fish and trying to take a bite.
4. The camera vehicle rarely needs to be going over 35-40 mph, and the subject car only has to quickly accelerate from below that speed, starting from about four car lengths behind, to zoom up on the camera car like the aforementioned shark. Dodging side-to-side by the subject car (the camera vehicle stays on its trajectory) makes it look very menacing.
5. If you want to spice it up even further, try it on a curvy road, but the difficulty level goes up by about 300%.
6. Do it in the wet or on a dusty road, and it's 1000% as difficult, but produces some cool effects.
Crossboss can probably add some of his favorite techniques too.