I have been getting my parts shipped to Hagen's of Blaine, but I recently signed up for this friendly postal service. I just came back from the states, no border waiting times!
You receive a pin on your email (as well as a text if select the option) once your package arrives.
You enter the pin when you're at the main door to get in. Then you punch in the same pin inside the building and you will see a compartment pop it's door open with your delivery inside.
It's a nice system, however, beware because it feels like you're up to nothing but a break and enter though while entering the pin to get in at midnight.
Oh...and FYI, for those of you who go to the Peace Arch or Pacific X border, surprisingly the Shell nearby on 360 D Street has the cheapest gas 99.9% of the time.