Any parent who has tried to install his child's car seat in more than one car knows how different the experience can be from one car to another. A new study by the Insurance Institute for Highway Safety (IIHS) and the University of Michigan Transportation Research Institute (UMTRI) finds that less than 25 percent of the top-selling cars, Minivans, Wagons, SUVs and Pickup Trucks have LATCH designs that are easy to use. LATCH, which stands for lower tethers and anchors, was introduced in cars in the 2003 model year and was created to make child safety seats easier to install properly.

The IIHS/UMTRI study assessed the LATCH fixtures and the rear seats of 98 of the best-selling vehicles for the 2011 model year. Researchers determined that there were three factors affecting whether the LATCH anchors were used properly: depth of the anchor in between the seat back and seat bottom; clearance to the anchor associated with the vehicle seat itself or other hardware, such as the vehicle's seat belts or buckles; and force required to connect the car seat to the LATCH anchors. Cars that were determined to be good in all three areas were 19 times as likely to have the anchors used correctly by the volunteers participating in the study than cars that didn't meet any of the criteria. Study volunteers used LATCH anchors correctly just 60 percent of the time.

Overall, 21 of the 98 top-selling cars researchers studied met the three criteria for an easy installation.

They were:

· Audi A4 Quattro

· Cadillac Escalade

· Chevrolet Equinox LT

· Chevrolet Silverado 1500 Crew Cab

· Chevrolet Suburban LT

· Chevrolet Tahoe LS

· Chrysler Town & Country (2010)

· Dodge Caliber Mainstreet

· Dodge Grand Caravan (shown here)

· Dodge Ram 1500 Crew Cab

· Ford Escape XLT

· Ford F-150 SuperCrew Cab

· GMC Sierra 1500 Crew Cab SLE

· Honda Pilot EX-L

· Kia Sedona LX

· Land Rover Range Rover Sport

· Mercedes-Benz C-Class C300

· Mercedes-Benz E-Class E350

· Mitsubishi Eclipse GS Coupe

· Mitsubishi Lancer ES

· Toyota Tacoma Extended Cab

By contrast, researchers did not find a problem with the tether fixture in vehicles, but instead found that volunteers either didn't use them or didn't use them correctly, such as by having a twisted strap or by not tightening the strap enough.