We transported our two 17 year old cats from Michigan. They began in cat carriers but by the time we traveled 100 miles their "howling" drove us nuts.
Being we have a hatchback we already had the back seats down so we ditched the carriers and let the cats run free. They stopped their howling, walked around (sometimes to the front seat to sit on my lap or lay at my feet) and slept a lot in the back of the car. They were happier than ever for the entire 1100 miles. Of course we had litter boxes, food, and water in the back with them.
I'm glad we decided to get a car top carrier for our personal belongings or we'd been in a heap of trouble...
