Illegal To Have Dog Just Sitting In Car ?

[Whippets Rule]

Currently my dogs are just loose in the 4 x 4 as it is a true off roader and only has two front seats and no rears so the dogs are basically lower down in the vehicle but our new car comes on Tuesday and it has a dog guard.

I never tie their leads to anything as I know of a couple whose dog broke it's neck when they had a bump too.