In order for any car seat to be sold in the United States, the product must pass safety ratings and crash tests.

It's not possible to determine the safest car seats based on these tests, because the manufacturers aren't required to make the test results available–and so they never will. Still, we can at least be confident that each car seat sold in the United States matches or even exceeds governmental requirements.

You can find out which car seats are safest through Consumer Reports, which does simulated car crashes to test the effectiveness of car seats. However, we should also note that scientists have discounted the results for various reasons. Sometimes it's because of past mistakes, or because of poor parameters and less than good reporting. Still, Consumer Reports is a good place to begin your research.

Consumer Reports has written about its top picks over the years. Do remember, however, that even the safest car seat in the world is only as safe as the user. If you don't install it properly or use it properly each time your child rides in the car, then of course it's not safe.

Recently Consumer Reports conducted a test involving rear-facing infant car seats. This was an effort to make up for the previous year's test, which had errors. All the seats they used (eleven in total) passed crash test standards as defined by the government when secured with a seatbelt and when using the LATCH.

(LATCH stands for Lower Anchors and Tethers for Children.) Again, we find the United States' pass/fail system fails to provide us a "best" and "worst" model.

Consumer Reports recognized this and tried to figure out which were the safest car seats by adding a rating system for Ease of Use and Fit to Vehicle. Both of these will be important factors in a car seat's safety.

You won't be able to install the car seat safely if it doesn't fit properly in the car. If the car seat is difficult to install, someone is more likely to install it improperly and unsafely.

With these guidelines, Consumer Reports rated the Chicco Key Fit as the best or safest car seat, with the Britax Companion coming in second.

For the Best Buys, Consumer Reports deemed Baby Trend Flex-Loc and Graco SnugRide as having the best value and features for your money.