Potty Training 101

So we have been trying to potty train Austin. I haven't attacked it too aggressively because we have been on vacation but now I am ready for the challenge. Austin will pee in the potty but has yet to do the other. He puts on a good show. He grunts and laughs. He knows if he does it he gets one of the matchbox cars we have sitting above the toilet. It's obviously not enough motivation for him. Any advice is welcome! Here is a picture of him doing his thing. He insists on having the Reader's Digest to read while he is on the potty. He cracks me up! Don't worry mom...I made sure his bits and pieces were covered.