Welcome back to the Lighter Car News, our semiregular roundup of automotive stories posted across the Internet.

This week, we’re asking “Why?” quite a lot. We look at why anyone would search for certified used Rolls-Royce models on an iPad, why a Missouri woman couldn’t stop her Kia Sorrento from reaching 120 mph, and why Audi wants to ditch its legendary quattro all-wheel-drive system.

If you already know the answers to all of these questions, have a fudge brownie and move on to our other coverage. If not, stay with us …

Finding the perfect certified pre-owned Rolls-Royces is so easy

Rolls-Royce may have us believe that its new online search tool has just made it incredibly easy to see the company’s entire stock of certified used cars. And they’re right -- because in the U.S., only four cars are in stock.

Keith Griffin, who covers the used-car business for About.com, thought it funny that Rolls-Royce made a big deal over a nearly nonexistent market. A week ago, Griffin did a search and found just three used -- sorry, “provenance” -- Rolls-Royce models under the company’s new directory. Might a whopping eight show up next week? (There are seven in Kuwait and 43 in the U.K.)

The best deal is a silver-on-black 2006 Phantom (above) with 4,488 miles for just $198,900. That’s a serious drop for a car that, brand new, cost more than double that price. The Phantom and a 2010 Ghost are in Houston, a 2010 Phantom Coupe is in Fort Lauderdale, Fla., and a 2009 Phantom Drophead Coupe is in St. Louis.

“Doesn't that make you wonder?” Griffin writes. “Who buys a Rolls-Royce and trades it in after just 3,000 miles?”

To me, the bigger question is why someone, other than nosy car journalists like Griffin and me, would bother to search for a used Rolls? If I had $200,000 to spend, I'd never think of shopping used, nor would I whip out the iPad and do a custom search. That kind of money demands something fresh and custom like a Mercedes SLS AMG, not a discarded Rolls. And more than likely, whatever business occurred on those champagne-stocked back seats didn't involve Microsoft Office. 

Sudden acceleration strikes again: Kia Sorento at 120 mph

Just when I thought people knew how to stop their cars from accelerating wildly out of control -- Toyota posted a step-by-step video on its recall site, as did every major news outlet -- there’s this. A woman in Missouri somehow couldn’t stop her 2011 Kia Sorento from reaching nearly 120 mph on Interstate 35. Luckily, police were able to escort her until she stopped -- 59 miles later.

Apparently, none of the car’s systems -- the push-button ignition, the gear selector, the parking brake, the regular brakes -- were working. In the video above, taken by Missouri State Highway Patrol, you can see the Kia still rolling as it comes to a stop, after the woman was advised by 911 responders to pull up on the throttle and hit the brakes at the same time.

Several owners have filed complaints with the National Highway Traffic Safety Administration regarding sudden acceleration on the 2011 Sorento, including one man who apparently had to hit a tree on someone’s property in order to stop the car. However, a car’s brakes should overpower an open throttle, even at speed (although it’s tougher, as Popular Mechanics describes).

We don’t know when this woman applied the brakes or how she applied them. Too little force can reduce brake pressure when the brakes are then fully applied; at higher speeds, the brake rotors and pads can overheat, causing fade. Even so, the fact that the shifter and ignition switch don’t work are either serious concerns for Kia or another wake-up call to American drivers on how to handle this alarming situation. I’m betting it’s the latter.

Audi to replace quattro with electric all-wheel-drive 

According to Jens Meiners, the trusted European correspondent for Car and Driver, Audi wants to replace its beloved quattro system with e-Quattro. The new system would use batteries and an electric motor to power the rear axle, the engine to power the front axle, and no driveshaft or central differential to split the torque.

The perceived benefit in fuel efficiency and space -- the lack of a driveshaft could do wonders for interior room -- might not make sense when the cost and complexity of batteries come into consideration. Reliability is another major concern. Meiners says e-Quattro will come anyway, possibly in the next two to three years, and will eventually kick the mechanical quattro system that has led Audi to numerous racing victories (and bans for being too good) out the door.

However, it’s not too surprising. Audi has been developing hybrid all-wheel-drive systems for more than 20 years. In 1989, the Audi Duo, based on the 100 Avant, used a 5-cylinder engine up front and an electric motor in back (pictured above). The idea was further refined on the 1997 Duo, which could run independently on its electric rear axle. Only 100 were sold. Volvo is selling such a system on its diesel-powered V60 Plug-in Hybrid, sold only in Europe. At the touch of a button, the driver can switch powertrain modes for efficiency or performance, so that one or both of its axles are driven at a time.