I had heard stories about hour long waits, but that was not the case for us on a rainy Saturday morning. The regular line looked to be fairly short, but since we filled out the info online, our line was non-existent! There was a couple at the window, then it was our turn. Bring cash to avoid the debit card fee.
There are hustlers outside, trying to lure you to their chapels. If you are on a whim and don't have one picked out yet, I guess you could score a deal! Otherwise, just let them know you have a place already and they back down.
As for parking, there is paid parking on the street. We dropped in two quarters just to be on the safe side... They watch and the fine is $20, so don't cheap out on that quarter! Lol. :-)