I have seen the other thread about the booster seat but I was wondering if anyone has a larger type that the dog can lie down in? We have a vacation home that is a 4 hour drive. Audrey doesn't mind the drive and usually sleeps a good part of it but on our last trip she wanted to look out the window more than before. I'd love to find a safe booster seat she could also sleep in. I have seen several on the internet but not sure what might be best and safest.