Borders...not the book store (no apostrophe!)

Each time I cross the US-Canadian border, things go less than smoothly. It seems that my choice of a nomadic lifestyle is aggravating this situation. Yesterday, I came back from Quebec, Quebec and, because I had passed through one of the primary border inspection stations (Derby Line, VT) the previous day, I decided to go through a more remote location (Beecher Falls, NH -- which looked more like a pull-through gas station than a national border crossing) just to see two different routes. I had passed through a heavy thunderstorm along a soft dirt/gravel road (another story, another time), so it might have looked like I was trying to sneak across. He searched my car trunk, handed my passport to his coworker who took it inside to check out, and looked really annoyed after closing the trunk because his hands were now quite dirty.  The interrogation went a bit like an Abbott and Costello routine. The whole event took about 10 minutes, but it's not like we were holding up all the imaginary traffic that goes through at Beecher Falls.  I now attempt to recreate the highlights as accurately as possible:

Officer: Where do you live?
Me: Boston these days.
O: Where are the car plates from?
M: It's registered in Oregon.
O: Is this your car?
M: Yes.
O: But you said you're from Boston.
M: I'm living there for two months. I change states every two months for work. I'll be moving to DC next month.
O: How long have you been in Boston?
M: A little over a month. I'll be moving to DC next month.
O: I don't get why your plates are from Oregon.
M: Let me show you my driver's license (Oregon). Does this help?
O: Not really. Where are you from? [I think he asked this because my passport is California].
M: I'm from CA, but I moved to OR in February for four months. Then I moved out here and change states every two months [I explain the whole Cirque business].
O: So the car is from Oregon?
M: No, it's actually from California, but I re-registered it in Oregon.
O: Does the job pay well?
M: Not really.
O: Then why would you do this?