One of the guys who regularly posted videos on e60.net had a set up which allowed him to combine info from his v-box type race data capture system with his video.
His videos had a little information frame around them indicating the following in real time:
1. Wheel Speed
2. Rpm
3. Level of steering input
4. Level of acclerator and brake input
5. Current gear.
If you really want to get the most out of this it might be worth looking into. It certainly made his videos more interesting.
You might also find this interesting:
http://www.qv500.com/onboard/index.php