During Bernadette and Amy's initial argument, when Penny says, "Damn!", it wasn't scripted.
Sheldon's explanation of why he prefers his old parking spot (it is a corner spot that reduces the risk of door-dings in half, it's very close to the building entrance, a nearby tree provides shade on hot days and is also home to a delightful squirrel) is very analogous to his explanation of why he prefers his spot on the couch from Pilot (2007) (In the winter it's close enough to the radiator to remain warm but not cause perspiration, in the summer it's directly in the path of a cross breeze from the windows, it faces the television at an angle that is neither direct, thus discouraging conversation, nor so far wide to create a parallax distortion).
Howard finally gets rid of his motor scooter that was the butt of many jokes for over five years.
Sheldon mentions that Howard returned from space five weeks ago. This is indeed the fifth episode after Howard's return in The Re-Entry Minimization (2012), so with a weekly broadcast schedule, roughly the same time pass between episodes as in real life (with some exceptions).
A picture taken of Howard and Bernadette when they were dressed as Smurfs in The Holographic Excitation (2012) can be seen on the stand behind Bernadette and Penny as they look at Bernadette's wedding pictures, and Howard's NASA portrait first seen in the same episode is standing on a desk in the background.