I saw it out of the corner of my eye and at first it didn't trip my early warning radar...and then I thought, "Wait, that's way smaller than it should be." I wound up grabbing the camera off the table and jogging to the corner. Stupid Ricoh GXR with the A16 module booted up too slow to get more than one shot before the light turned green and I missed focus.
(Earlier I'd missed a BMW 3.0 CSi.)