Cool car features you can buy now

New high-tech systems are popping up faster than you can say microchip. These five aren't mainstream yet but may catch on.

1. Inflatable safety belts. Ford has started offering rear safety belts that have mini air bags stitched inside their webbing. If activated, these belts inflate to five times the width of a conventional belt. The extra width helps spread the force of an impact on a passenger's body more effectively than standard safety belts and can help reduce neck and chest injuries in severe crashes. Ford says the potential benefits are greatest for the elderly and the young, and for small passengers who don't fit well in regular belts. They're now available on the Explorer and Flex SUVs and will be an option for the 2013 Lincoln MKT SUV and MKZ sedan.
2. Guided tire inflation. Nissan has eliminated one more excuse for not keeping your tires at the right pressure. With its new Easy-Fill Tire Alert system, you simply grab an air hose or compressor and start filling an underinflated tire. When the tire reaches the proper pressure, the car will chirp its horn to let you know when to stop. While the tire is inflating, four-way flashers are activated. If you add too much air, the horn beeps more aggressively. Then, when you bleed air out, the horn will chirp once more to indicate you've reached the proper pressure. The system is now available on the Nissan Altima, Leaf, Pathfinder, Quest, and Sentra, and the Infiniti JX.
3. Fatigue monitoring. Mercedes-Benz' Attention Assist system is designed to detect when a driver is in danger of falling asleep at the wheel. It monitors about 70 parameters related to a person's driving behavior, including how much time you've spent behind the wheel and any notable variations, such as more-erratic steering inputs, unintentional lane departures, and infrequent use of the vehicle's controls and switches. If the system concludes that you could be getting drowsy, it issues an audible and visual warning to suggest it's time to take a break. We think the concept has potential, although it has seldom sounded an alert in the models we've driven that have it. Similarly, Subaru's Lane Sway Warning system is designed to detect a vehicle drifting out of its lane because of driver fatigue or other variables.
4. Foot-operated trunk and tailgate release. This handy new feature makes loading groceries or luggage easier by eliminating the need to fumble for keys when your hands are full. Just swing a foot under the rear bumper and the trunk lid or hatch door opens up. The system requires that the car have an optional keyless-entry system, which senses when the ignition key is nearby and allows you to lock and unlock the doors without having to pull the key out of your pocket or purse. The system is available on several BMW models as well as the Ford Escape and C-Max.
5. Active noise cancellation. Think of this as noise-cancelling headphones for the car. To help isolate passengers from annoying outside noise, the system uses microphones to listen for certain sound waves in the cabin, such as those produced by road or engine noise. When they are detected, the system generates an opposing audio signal through the speakers to cancel out the offending noise. It's available on the Acura ILX, RDX, and TSX; Chevrolet Impala; Honda Accord, Crosstour, Odyssey, and Pilot; Ford C-Max and Fusion hybrids; and several Cadillac and Lincoln vehicles.