Well, you can go with manual or electronic actuation. A while back I had designed an automatically actuated block for my Matrix. Unfortunately, I had some fitment problems and never got it on the car before I got my Prius. I can say that the opening method I had didn't work very well. It bound up, especially once you put it on the car which made it bow.
http://ecomodder.com/forum/showthrea...ed+grill+block