See also:

Rear seats
WARNING Seatbelts provide maximum restraint when the occupant sits well back and upright in the seat. Do not put cushions or any other materials between occupants and seatbacks or seat cushions ...

Example of the type of accident in which the SRS curtain airbag will basically not deploy.
The SRS curtain airbags are not basically designed to deploy if the vehicle pitches end over end. ...

Recommended grade and viscosity
Each oil manufacturer has its own base oils and additives. Never use different brands together. For details, refer to “Manual transmission, front differential and rear differential gear oil” F12-6 ...