Border agents can tell somebody's hiding inside a car without opening a single door. Every time your heart beats, it rocks the whole vehicle a tiny bit, and they've got sensors sensitive enough to feel that through two tons of van. So the guy in these photos was in trouble before he even reached the booth. This was San Ysidro, the crossing between Tijuana and San Diego, back in 2001. An INS inspector checked the back of a van and found a 42-year-old man folded up inside the passenger seat's…