Unless your pet can be picked up with minimal effort, you'll need to create an easy way for your pet -- especially a large breed dog -- to get in and out of the car easily. While some dogs may jump in without a care, others may be intimidated by the height difference between the ground and your vehicle and may be wary as a result. Older or arthritic animals can especially have a difficult time getting in or out. One choice is to use a short ramp that the dog is trained to walk up, but they can be cumbersome to store inside the car and some dogs won't use them. Another option is the Twistep, a 20-inch by 20-inch platform that plugs into the receiver hitch on a pickup or SUV, and then twists under the bumper when not in use. The dog simply uses it like he would a stair to enter or exit the vehicle.