We're going on a trip, and planning to take our 3 year old miniature American Eskimo. Long car...?

She may feel safer is a crate or carrier rather then being lose in the car. Some dogs feel more secure in a carrier when in a car. My dog will pant on occasion also when traveling, but I think that is due to him being hot. If you don't think she is going to do well on the trip, then leave her with a sitter.