Car seats are the law – and for good reason!
Don’t buy a used car seat or borrow one from a friend who used it for her kids. It may not be the safest option, as safety regulations change with time and improvements are being made constantly, especially when it comes to the safety of children.In addition, if a car seat was involved in an accident, it cannot be used. Always check labels to make sure the car seat you choose meets current federal safety standards
There are two ways in which a car seat may be secured into your vehicle. Cars manufactured after Sept. 1, 2002 use a LATCH-equipped car seat with lower anchor attachments and top-tether anchors. Cars manufactured before Sept. 1, 2002 will use the car’s seat belt system to safely secure the car seat in place.
The safety of car seats involves not only properly installing the seat into the car, but also, using the harnesses correctly to secure your child. Check the straps for a proper fit each time you put your child in the seat. The straps should be snug and the harness retainer clip (or the chest clip) should always be secured at the lever of the child’s armpit. You should be able to pass no more than one finger between the shoulder harness and the child’s collarbone.
If you have two cars that you and your partner use, you may want to buy a second base for their other car. This is a matter of preference and convenience but many people find this to be more manageable than un-installing and re-installing the car seats each time you need to switch cars. Since children grow and change, so should their car seats. You must consider the height and weight of your child when you buy.
Fit – The car seat must be appropriate for your child’s age and weight. It must also fit in your car appropriately so to avoid extra hassles, be sure to try out the fit before buying, especially if you drive a smaller vehicle
Adjustability- Tightening or loosening the harness should not be rocket science! Some car seats require that you uninstall the whole seat in order to change the height of the harness. Save yourself the trouble and look for car seats that adjust the harness height without the need to uninstall and reinstall the seat. 
Never buy a car seat if does not have this symbol (National Safety Mark) on it, as it does not meet Canadian Safety standards. That could not only mean a big ticket from police but it