This Wired News article explains perfectly a frustration I've had with modern motor vehicles. Soon after buying my Corvette, I found out that handheld units existed that would let me dump the factory data out of the 'vette's computer and into the device, overwriting the existing programs with custom-tuned programs. To me, the big question was "Why don't a get a CD and an interface cable with the car, so I can tweak this stuff with my laptop?" Well, I guess the answer is "Because mechanics want to charge me for this capability and if I get this stuff from the factory, they won't be able to make money."
Same frustration with my 2002 Cannondale Cannibal ATV. The only difference between this quad and the next one up (the Speed) the line is some tweaks to the computer. Bump the Cannibal's rev limiter up to 10,000 RPM and adjust some of the curves and you essentially have a Speed. But the interface cable and software are proprietary, so there's no way to do this without visiting a Cannondale-certified mechanic or paying over $1,000 to buy the stuff on the black market or on eBay.
So now we might get a law that will force auto manufacturers to turn over this information. Sounds good to me. I hate not being able to work on my car myself.