It depends on the size of your cat for a carrier.
I have one of those lovely pink open at the top and front ones for Lupin but they are quite small and unhelpfully cant think of the make!
Misa is so big he needs a cage and no way should a cat travel in a car without being in a carrier, they cant be treatewd like dogs cos they dont act like them
Yes cats can get out of the open style harnesses but not out of the walking jacket type ones which are fitted using velcro. It all depends whether you put it onj snuggly enough! It was too loose in these pictures.
I had Lupins made by a company who makes to measure and its really great...............he doesnt think so though