Volvo recommends that children travel in rear-facing child seats until as late an age as possible, at least until 3-4 years of age, and then front-facing booster cushions/child seats until up to 10 years of age.
The position of a child in the car and the choice of equipment are dictated by the child's weight and size; see Child seats.
Regulations regarding the placement of children in cars vary from country to country. Check what does apply.
Volvo has child safety equipment (child seats, booster cushions & attachment devices) which is designed for your particular car. Using Volvo's child safety equipment provides you with optimum conditions for your child to travel safely in the car. Furthermore, the child safety equipment fits and is easy to use.
In the event of questions when fitting child safety products, contact the manufacturer for clearer instructions.