A key point to keep in mind: Don't make sudden movements with your hand. (choosehamstercages.com)
The carrier should be big enough for them to lay and sit up comfortably, but should not leave too much room in case of any sudden movements. (petsmagazine.com.sg)
So it is better to drive slow and smooth in winter and avoid sudden movements of breaks to reduce the chances of damage. (calgarydriving.ca)