The green bike (I believe it was a Klein Rascal originally, which was stolen and replaced for a while by a blue and white Cannondale before another green Klein, this time an Adroit, replaced that) first appeared in Season 3. The old Mac was still there. Watch https://www.youtube.com/watch?v=g7JPliFLgR8 starting at about 5.30 and you can see them both in the same scene.
