Incidentally, in one epsiode Leela actually crashes into the billboard within the context of the show and Fry says, "that's the second time you did that this week!" This suggests to me that maybe the opening sequences is supposed to actually happen each week. In other words, she really does crash into it once a week when returning from delivery runs.
Or at least that one week.
It's pretty similar to a joke from the Simpsons episode "Lisa's Date with Density," where Lisa, forced to write on the blackboard as a punishment, asks how Bart does it every week.
I think it's probably more likely that Bart writes on the blackboard every week than that Leela crashes the ship into the same screen every week.