The new Minnesota DPS commercial makes my kids laugh when they see it, but of course it is making a serious point. New state data shows 52 percent of all children ages 4 to 7 who were passengers in car wrecks from 2006 through 2010 weren't properly secured in booster seats. The rate was worse in car wrecks in which the children were injured: 62 percent of the injured children weren't properly restrained. And the rate was even worse when these children died: 7 of the 9 fatalities involved children ages 4 to 7 who weren't properly restrained.

Compliance with state child safety laws is better when children are newborns and infants, but drops off when children reach preschool and grade-school ages. The most common mistakes, according to the state:

Turning a child from a rear-facing restraint to a forward-facing restraint too soon.

Restraint is not secured tight enough — it should not shift more than one inch side-to-side or out from the seat.

Harness on the child is not tight enough — if you can pinch harness material, it's too loose.

Retainer clip is up too high or too low — should be at the child's armpit level.

Child is in the wrong restraint — don't rush a child into a seat belt.