want to go camping and take the dogs with me jack russel and westie got a cage for the car which they r used to going in alot the only thing that i am worried about is if we can't leave them in the car i was going to get a battery fan for there cage and leave all the windows open a bit in the car how long could i leave them in the car for if i left all 4 windows down a few inches with the fan on there cage also any good places in the south or south west where is dog friendly togo camping and any other tips please