when i came back from my trip to cozumel and grand cayman they pulled me aside and were asking me all sorts of prodding questions. i was like WTF is wrong with you guys? you can let them know that they are going to far. ask them why they are stereotyoing you. i did. i accused them of profiling me because i had a goatee and was singing in the waiting line
turn the conversation on them. instead of being defensive, be offensive. they got me out of their hair as soon as possible. those checkpoints are there to screen people, not interrogate guilty citizens. those guys do the same thing all year long every day of their lives. they hate that duty.
when i go through customs i always make it a point to never act like i want to pass their test. 99% of the people go up to them expecting a quiz that they want to pass just like in high school. if you want to get through their shit asap, just act like they are an inconvenience to you and like you could give a lesser shit what they ask and they won't even give a shit about you. if you show any fear or concern about what they are asking they will dig and dig and try to find shit to fuck with you.
just my opinion. works for me.