don't put your kids in boosters. They only work front and rear impact, I could toss my kids right out of them in a turn. Best to have them in the back with a waist belt, not a shoulder belt. I hit corners hard on purpose, if I hear a thud I yell out "why do we wear out seat belts?". And the boys would chant "to keep our butts in the seat daddy". They drive nothing nowhere with out seat belts, even the motorhome.
When 3 the twins were in a seat belt and the third was still 2 in a car seat, all in the back of the van. Some guy pulls out in front of my van and I hit the brakes hard. The twins unclicked Robbys seat belt and him and the seat flew through the van, he was in the back in front of the gap of the middle seat. He was fine but scary to watch him and the car seat flying. I would load 3 every morning to go to work, which means one at a time. Once in a while the first kid would jump out and try to move the car. There is a LOT to dealing with children in the car. One twin crashed my blue truck into my dads truck, engine off. The other twin crashed my one ton into the GLHS, the GLHS was saved by the truck door, again engine off. Robby today took up smoking and to hide from me he thought it would be smart to smoke in my new PT.... It is endless, always make there safety higher than what the law demands. If they can't be safe in the car seat for there age, in one car and not the other, don't use it. Thank god I learned about booster seats in the winter with the windows up!