(National Highway Traffic Safety Administration)

Using a child seat is the most important thing you can do to keep your kids safe in a car accident. Yet studies show that the vast majority of child car seats – as many as 95 percent according to some studies – are incorrectly installed. What can you do to avoid this misstep?

Why Kids Need Car Seats

Standard seat belts are designed for adults. Kids’ bodies are different; they're both smaller and less developed than adult bodies. So they need protection specifically designed for them. Most toddlers, for example, are still too small to fit in a car’s standard seat belts. The shoulder belt would cross their nose or their neck, and lap belts would cross them at their most vulnerable point, in their abdomen, rather than their hips. Worse, they may fly out of the belts altogether in a crash.

[Which Car Seat Is Right for Your Child?]

Child seats can adapt the standard seats in a car to protect kids’ smaller bodies and their developing bone structure. The five-point harnesses in child seats hold kids tightly at their bodies’ strongest points – their shoulders and pelvis. If the seat isn’t firmly attached to the car, either by the car’s seat anchors or its standard seat belts, it won't work. Kids under two years old are 75 percent less likely to die in a car crash if they’re in a properly secured rear-facing seat, according to the National Highway Traffic Safety Administration.

How to Correctly Install Child Seats

To work correctly, the child seat should not be able to move more than one inch in any direction once it’s attached. Rear-facing seats should also recline between 30 and 45 degrees, so that a baby’s head can’t flop forward and restrict breathing. Often, this means an adult needs to physically climb onto the seat with at least one knee to put enough pressure on it to get the straps tight enough. Most modern child seats should be designed to sufficiently recline, while many have level indicators to help guide parents. The old advice – to install a rolled-up towel underneath the seat to level it – is obsolete, certified installers say.

Why LATCH Anchors Don’t Always Work

Since 2002, automakers have been required to build Lower Anchors and Tethers for Children (LATCH) into all cars. These connectors are designed to attach to straps or arms built into child seats and make it simple for parents to cinch them down securely. However, LATCH anchors won’t always work. The anchors themselves are sometimes hard to get to. They can be set deep behind plastic covers on the seats. Most cars don’t have LATCH anchors in the center rear seat where kids are safest in an accident. And in most cars, LATCH anchors are only rated for kids up to a maximum of 45 pounds. Yet many of today’s kids grow right through that weight limit before they are old enough or tall enough to graduate to booster seats. So even though the seats are designed to hold kids up to 65 pounds, you may have to install the seat with the car’s seat belts.

When you use LATCH, you also need to secure the top of the seat to a top-tether anchor in the car. Some cars’ top-tether anchors, however, are inaccessible without folding or pulling the rear seats forward – out of position to install a child seat.

(National Highway Traffic Safety Administration)

Sometimes Seat Belts Don’t Work Either

Whether your child has outgrown your car’s LATCH anchors or they’re not accessible, you sometimes have to use a car’s seat belts to get a proper installation. Yet the seat belts aren’t foolproof either. Sometimes the contour of the back seat doesn’t allow the child seat to sit tight against the seatback, or the belt's buckles are mounted so far forward of the seatback that they can’t cinch the child seat tightly against it. Either way, the child seat won’t sit tightly enough.

In some cars, even if the belts can adequately secure a child seat, there isn’t enough room behind the front seat to recline a rear-facing infant or toddler seat properly behind the front seats. You may have to fold the front seat forward and forego carrying a passenger there.

Choose a Flexible Car

Every car is different, and so is every child seat. Since kids outgrow infant and toddler seats, they will need at least three seats before they grow into the car’s native seat belts. Cars last a lot longer, so your best bet is to find a car that easily fits the widest variety of child seats.

It can be a challenge to find cars that are compatible with all types of child seats in a way that allows them to be easily installed. When you’re shopping for a car, it’s important to bring your child seats along and try installing them using LATCH anchors and the car's seat belt. If it won’t fit securely, look for another car.

[U.S. News Best Cars for Families]

The Insurance Institute for Highway Safety (IIHS) provides some guidance by rating cars’ LATCH anchor systems for ease-of-use. Unfortunately, only three cars earn Good ratings in their evaluations: the Volkswagen Passat, the BMW 5-Series, and the $70,000 Mercedes-Benz GLS SUV. Since Europe adopted LATCH anchors for child seats years earlier than the U.S., it makes sense that it builds the cars with the easiest anchors. If none of those high-end German vehicles suit your needs, however, the IIHS gives 44 more cars Acceptable LATCH ratings. You can find them on its website.

Volkswagen Passat

When you think of Volkswagen, you don’t usually think of a sedan this big. However, the Passat’s big back seat and easy-to-reach LATCH anchors make it easy to install a wide variety of child seats.

For a German-branded car, the Passat is about as American as you can get. It’s wide, long, and comfy – and built on an American scale in Chattanooga, Tenn. Front and rear seats are designed for passengers with plenty of girth, as well as long legs and torsos.

Volkswagen Passat Rear Seat
Volkswagen Passat

The Passat comes with an efficient and punchy four-cylinder engine that delivers an impressive 29 mpg EPA rating in combined city/highway driving. You can also opt for a potent V6. To make sure your family stays as safe as possible, the Passat is available with the latest in active safety features: automatic emergency braking, lane keeping assistance, blind-spot monitoring, rear cross-traffic alert, and a back-up camera. That might be expected in a more expensive German luxury car, but they’re available on the Passat for just over $27,000.

BMW 5-Series

The 5-Series costs a lot more than a VW Passat, and doesn’t have as much room inside, but it is jammed with technology and has one of the easiest child-seat LATCH anchors to use.

Available with either rear- or all-wheel drive, the 5-Series offers a choice of turbocharged four-cylinder, six-cylinder, and V8 engines, including a six-cylinder turbo-diesel and a six-cylinder turbocharged hybrid.

Like other $50,000 sports sedans, it offers automatic emergency braking, along with adaptive cruise control that will creep the car along in a traffic jam by itself, although that package adds a hefty $2,900 to the bottom line.

Mercedes-Benz GLS

The GLS, formerly known as the GL, is Mercedes’s largest and most expensive SUV. If you’re looking for the ultimate family truckster, with three rows of seats and easy-to-use LATCH child seat anchors, you can’t beat the GLS.

You can order a GLS with any of three twin-turbocharged gas engines (a V6 or two V8s), but the standard engine is a turbodiesel V6 that is EPA-rated at 22 mpg in combined city/highway driving. That may not sound like much, but for a three-row SUV with this much power, it’s pretty darn efficient.

All three rows should have plenty of room for child seats, and with its full suite of active safety systems monitoring all sides of the car, it would be hard to find a safer family hauler.