I use a black and blue small carrier from Amazon for Wick’s visits to the vet (10min). It’s enough for him to move and turn and lounge, and I can just plop a pillow case and pee pad in it and replace as needed if he pees.
http://www.amazon.com/gp/aw/d/B01LZUV8I5/ref=ya_aw_oh_bia_dp?ie=UTF8&psc=1
For long car rides, I have a medium sized carrier that attaches via seat belt, also found on Amazon. Generally, I’d say avoid putting things in larger carriers because one abrupt brake will make objects fly into your rabbit, or your rabbit fly into an object. For long car rides, it’s best to make pit stops for a litter break and food and water.
http://www.amazon.com/gp/aw/d/B00CLA12Y0/ref=ya_aw_oh_bia_dp?ie=UTF8&psc=1
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.