Cross link to
www.autoblog.com (via slashdot):
Automakers to gearheads: Stop repairing cars
Probably nothing new to most people here, but it's a good round-up of the various sides of the issue.
FWIW I'm all for user mods, but I'm also in favour of emissions testing - which gets hard when the user can easily implement something like "tap the brakes twice before cranking the engine => dirty high performance mode".
Not sure how this is best resolved, but one way would be to have a few EPA (or equivalent) approved fuel maps and ECU firmware mods publicly available, with modders having to pay a fee in the order of a few hundred dollars to get the modified code reviewed and cryptographicly signed. The obvious downsides of this idea are
(a) It's
highly unlikely the OEMs would go for it, I suspect they'd be as obstructionist about it as they could get away with.
(b) Properly vetting modified code would is non-trivial to say the least - particularly when you have mods like cylinder deactivation and you're worried about being sued by an SUV owner whose engine wouldn't start in the middle of a frozen wilderness.
(c) It would be way too easy for such a scheme to be arbitrarily shut down with no notice (much like the ability to run Linux on PS3s...).