There are some easy steps you can take to reduce the stress of a wildlife casualty while you're transporting them!
You can reduce stress by:
Keeping noise to a minimum - turn off your radio and use headphones if you want to listen to music.
Covering the box with a towel to reduce light and sound.
Making sure the box is secure - use a seatbelt to stop the box from moving around.
Keep handling and human interaction to a minimum.
Reducing stress not only makes the journey more comfortable for the casualty, but also improves their chances of recovery and limits the chances they will do further damage to themselves.