Yes, try the PREMO Kneebak Pillow, which is only 2″ thick, wider at the base (11″) and deeper so it raises your legs just enough to keep in comfortably in your chair.  You can also flip it around and put it behind your low back to fill in where your car seat or chair fall short to support your back.  Seniors especially love the Premo because it fits perfectly in their car.