I am not sure of the specifics on this one. It is either 5 seconds over the course of the game, or 5 seconds without hitting anything. I unlocked it by weaving side to side down a wide street. I would use the handbrake (
) and turn, then straighten up and do it again. It unlocked shortly after.
I avoided everything on the road as I did this. Will need more input from people on if they got it randomly or were trying for it to know if hitting things voids it.