Take a look at these pictures and see if you think you can. In my experience, no - and believe me, I have tried it in the car without removing the heads or the crank; it don't work even with the crank out.

http://home.koping.net/u3243a/images...s/DSC01323.JPG

http://i.ebayimg.com/images/i/110890...-1/s-l1000.jpg

.