Its just a data recorder - speed, engine rpm, manifold pressure I would guess are the things being recorded. What I'd really like to see are in-cabin microphones.
"So did you hear about Marge? Her husband was fooling around with his secretary and she only just found out yesterday when a clinic called about an appointment. I tell you, you just never know.... OH SWEEET JEBUS!"
"Duuuude, like this ride is so totally tricked out. Hey, let's see if it'll push up past 80... OH SWEEET JEBUS!"
"Aw, man. Dropped my cd case. Let me just reach over past the passenger seat and get it....OH SWEEET JEBUS!"
"Hey, hand me another beer... OH SWEEET JEBUS!"
"OH SWEET JEBUS!"