I think Detroit CBP operates out of a trailer park because they want to move it to Detroit River International Crossing when it gets opened. The owner of the Ambassador Bridge takes the word "AH" to new extremes. He owns the largest border crossing in the US but has sued US Customs to try and extract more rent, screwed with the State of Michigan, defied court orders, and is guilty of massive astroturfing. Rather than trying to make friends with Government to expand his bridge, he has nickel and dimed everyone while pleading poverty.
He has also stood in the way of most favorable development around that bridge. The area will never be great, but it could be made a little more friendly. It is a funny site, when you go out to lunch on Huron Church Road (the Canadian side) near the Bridge, you often find US border agents eating there. Other than Mexican Village, there is nothing on the US side.
I was told by US CBP agent that he started up with them when they put a couple of employee only picnic tables on an unused patch of grass near their plaza.
The bridge has also cut Windsor in half and turned one of their busiest retail streets into a virtual parking lot.