This is a guest post by automotive columnist Eric Peters.

Big Brother may be about to get just a bit bigger.

General Motors just announced a new and improved version of its OnStar telematics system that could be used to shut your car’s engine off (or at least, cut back the power) remotely.

Touted as a “safety” feature (of course), the upgraded version of OnStar would give external authorities (law enforcement – and, of course, GM) the ability to send out a signal keyed to the car’s on board computer, which in turn would ease off the gas – no matter how hard you’re putting foot down. GPS-equipped cars already can be located in real time at any time, whether moving or stationary. The “enhanced” version of OnStar would, however, be the first use of satellite technology to physically control the vehicle/supersede the driver.

The system goes live in 2009, when GM will begin offering it on more than 1.7 million new cars and trucks. Chevrolet will lead the way – with up to 60 percent of ’09 models fitted with “enhanced” OnStar.

So what’s wrong with the idea? Is it cabin-in-the-woods paranoia to be concerned about what, after all, could be a valuable tool for law enforcement?

The answer depends to a great extent on how much you trust the government.

Certainly, the use of “enhanced” OnStar to stop high-speed car chases and retrieve stolen cars is hard to argue with. But will that be all the technology’s used for?

Consider this:

The insurance industry is at this very moment lobbying Congress to impose electronic speed governors on heavy trucks – limiting them to no faster than 68 mph.

Surprisingly, the trucking industry isn’t completely opposed to the idea – provided electronic speed limiters are also fitted to ordinary passenger vehicles, too. Fair’s fair, right?

Now add a dash of “enhanced” OnStar to the brew.

Come 2009, it will be technically feasible to make speeding impossible. A modern car is controlled by computers; the computers are now tied into GPS systems such as OnStar – which have the ability to send and receive electronic transmissions, including instructions that tell the computer how to run the car. “Smart” speed limit signs can now be fitted with transmitters; when a car with “enhanced” OnStar comes into range, the transmitter tells the car’s computer what the maximum allowable speed shall be – and ye shall drive no faster.

Welcome to the future.

“Technology should not just entertain us or make us more comfortable,” croons NHTSA Administrator Nicole R. Nason. “It should make us safer.” Of course. And what could be safer than making speeding an impossibility? If you haven’t heard this argument voiced openly, just wait. It’s coming as sure as Lindsay Lohan’s next DWI. The safety nags have been patiently waiting for years for technology to catch up to their agenda.

Courtesy of GM, that day has arrived.

Our friends in the insurance and safety lobbies will soon be urging that this “optional” technology become a mandatory feature on every new car. Speeding is illegal – right? Who is going to argue in favor of allowing the automakers to continue building and selling cars capable of being driven 30, 40, 50 mph faster than the highest lawfully allowable maximum?

What about the children, after all?

And if that’s not alarming enough, consider the likely follow-up. Once all new cars are fitted with in-car speed nannies, the glassy eye of government will very likely turn its gaze upon older cars – especially older pre-computer cars, which can’t be electronically controlled because there is no on-board electronic controller. The old car hobby is already (justly) alarmed by recent changes in antique/classic car licensing and registration laws – which are making it harder and more expensive to keep an older car on the road.

In Virginia, for example, changes to the laws governing antique vehicle registration now empower police to conduct what amount to “road-side safety checks.” If the cop decides your antique vehicle doesn’t meet this or that jot or tittle of the law, he can seize your plates on the spot and have your antique vehicle towed to the impound lot – notwithstanding that most cops don’t have any specific knowledge of what is/isn’t “right” about decades-old vehicles.

Now the authorities have a new tool in their kit. A cudgel by which they cannot only beat speeders into submission – but which could very well be used to take older cars off the road forever. Consider yourself warned.

And remember to say “thanks, GM.”