Gross misuse includes failure to secure the seat at all, facing the seat the wrong way, or leaning it up against the air bag capsule. These are obvious, extreme dangers. A less obvious but more common mistake is to move children too soon from one stage to the other. Older children are placed prematurely into booster seats or even straight into adult belt systems. The next most common error involves not fitting the restraints correctly to the vehicle.
Seats differ substantially, model to model, in how they are fitted.
Because some seats are not well suited to certain vehicles, it's wise to try the seat in your own car before buying. The seat must be firmly strapped down. Some seats require a clip to be placed on the car's seat belt. These instructions always specify what size child the seat suits and depict just how to fit it. There may be a marked path for the seat-belt straps.