Opel Astra J 1.4 Turbo 2019 Owner's Manual page 57

Storage 55
detrimental effect on vehicle
handling due to the vehicle's
higher centre of gravity.
Distribute the load evenly and
secure it properly with retaining
straps. Adjust the tyre pressure
and vehicle speed according to
the load conditions. Check and
retighten the straps frequently.
Do not drive faster than
120 km/h.
The permissible roof load is
75 kg. The roof load is the
combined weight of the roof rack
and the load.