He will be in the boot with a guard to stop him getting loose, a cage would restrict him movements too much - he's a big dog and my car is not that big to take a cage.
Could you have him tethered in the car and then when you open the boot he can't escape while you put the lead on. Through a period of training you could do away with the lead once he has learnt that opening the boot doesn't mean 'run for the hills'.
Teach him to "STAY" so when you open the door he sits and waits, practice this in the car in a safe environment. The Sit and Stay commands are about the most important commands to teach any dog anyway.
That's what I was thinking. Have him tethered to begin with, train him to sit and wait while you put on the lead, after a while he knows that boot opens and he sits waiting for the lead to be put on or eventually for the command for him to get out the car.
Mine have 'seat belts' or harnesses that clip into the rear seat belt but you really need to teach 'wait'. Are you going to take him to training classes? If you are then that should be one of the things taught. Basically you need have him sit then say 'wait' and be able to walk away and then call him to come. You need to start small i.e. just a few steps. I also use 'wait' when we go for walks so I open the door and they wait till I go out first and then they can follow when I say 'come' and at every road we come to they wait till i say we can cross. It's a useful command and a basic for obedience.
My boot has two metal rings coming through the carpet that are attached to the chassis. I have a lead through these and then clip that lead onto dogs' collar - we have two dogs.
They are good but I don't ever want to be in an 'if only' situation eg broken down with two spooked doggies.
Cheers for that will look in hubbies car when he gets home - I know mine has nothing lik that but will look for other suitable items to attach the lead to.
Tethering a dog on a long lead can be very dangerous, excitable dogs can leap around in a moving car and strangle themselves. I always train my dogs to respond to the command 'Wait' - it has a sharper sound than 'Stay'- I start off at home when they want to go outside or by the front door. I've always had rescue dogs and it works in no time. Best of luck with your's.
I used bench tethers in a car till one of my dogs got wrapped in it and panicked, I had to stop on the side of the road and deal with a dog in a panic, i would never do it again. My dogs always travel in a cage in the car, they know to "wait" when I open the cage door until I let them go. personally I wouldn't rely on a command, things like loose cats and wasp stings do happen....If your car is big enough for the dog, in general its big enough for a cage!
I know of very many dogs that have escaped either during the journey to their new home of within a very short time. Please don't take any chances until he has been with you for long enough to know you and respond to you calling him should the worst happen. Hold him by the collar while you thread the lead through the bars of the dog guard, put the end of the lead through the handle loop and then clip the lead back onto his collar. This will give him room to move but stop him actually jumping out on opening the car boot. Take an extra lead with you so when you need to get him out you can clip the second lead on before releasing the first lead (in fact you could leave that one in there for next time). Also ensure he is either microchipped or tattooed before you get him just in case. Also get a dog tag for his collar with your phone number on which you can put on as soon as you get him