I know this post is old, but its always good to have lots of different answers when researching anything on the forum.
Mine crate together. I have 2 separate crates in case one is sick or in case they start to not get along in the crate together (like I thought would happen when Callie went into season). However, when I first brought Callie home, she was used to being crated with one of her littermates, so she did not like being crated alone. She escaped almost every day & destroyed my blinds (thank goodness that was all!). I started crating her with Lola, and although Lola gets testy when Callie won't settle down quickly, they both do very well crated together when I'm not home & when in the car. I can still crate them separately, but they prefer to be together so they can cuddle together & stay warm. I do always keep in mind though, it could go horribly wrong sometime when I'm not around. Its a calculated risk I take, but thus far it works out well as I have a small car and am forced to crate them together when we go anywhere.
