Last week one of the officers encountered this situation and snapped a picture:

Yes, that's a gas can strapped into the child safety seat, and the child, wearing a diaper is on the other side of the seat wearing a lap belt while the shoulder belt is behind him.
"Colorado law requires all children under age eight to be in a child safety seat when traveling in a motor vehicle. The law stipulates a minimum fine of $82 per violation.
Aurora Police said the driver in this case was written three restraint violations.
Police said the driver told officers the child lets himself out of the car seat. The officer then asked if the child put the gas can in the car seat and buckled it up, then buckled himself into a seatbelt on the other side of the car."