See also:

Child restraints
...

Reporting safety defects
For USA If you believe that your vehicle has a defect which could cause a crash or could cause injury or death, you should immediately inform the National Highway Traffic Safety Administratio ...

Seat belt extenders
If, because of body size or driving position, it is not possible to properly fit the lap/shoulder belt and fasten it, an extender is available which is compatible with the installed seat belts. ...