Espresso trucks/vans seemed to be a big thing in the EU when I lived there, but don't seem to have much of a place in the US. Maybe it's due to the low walkability of the US and tendency to travel via car? Or maybe it's hard to get the licensing for it?

I have found coffee carts not uncommon in the US (midwest and california). I think aside from the michoacana guy, food trucks and carts in the US tend to stay put for a long period of time, and really, you don't need more than a cart that you pick up with a truck at the end of the morning. I've seen coffee carts post up at entrances to offices as well as along bike and walking trails.