I do not travel with Nikki unless she is secured in her car seat (in the back of the car) She has a special car harness, (purchased at GW Little online) which attaches to the seat belt. The seat belt secures her Lookout Booster seat.
When she was a puppy, we brought her home in a soft-sided Sherpa bag.
Regarding crates, I used a crate to potty train Nikki. I actually had two Midwest crates (amazon.com has good prices) One of them was a 22X13 size, and set up on my nightstand right next to my bed. Nikki slept in there at night until she was potty trained. The other crate was 24x 18, and set up in the living/family room. We used it for daytime potty training. Nikki loved her larger crate. We just folded it up and put it away recently. (Nikki is 2 1/2.)
The potty training worked out well with 2 crates. If/when I get another puppy. I will do it the same way.