Traveling with pets

[Petrol Only]

I regularly travel 200 plus miles with seb. He's a pretty big lad. 25kg and all legs. He is in the boot of the car on his bed. Happy as larry. Is there anything else I should do? He can't fit through the gap so I don't need a dog guard? From reading the thread in GG dogs and two seaters. People chirping in saying have full harness etc and seatbelt for the dog. Maybe I'm being a bit lax with his safety?