Those long sweeping topes were jumps for me, the real bumpy ones I took pitty on my suspension compared to quite a few KLR riders I met (AND THEY have suspension issues...), but most of them I also used as passing opportunities.
Everybody thinks Mexicans are crazy drivers, but that's because (as you mentioned earlier) they haven't been in traffic with them. What they do works, and works very well. I could go through cities faster then I could ever imagine in a N.A city. Pass cars on highways with ease, and let cars faster than me (which most were) with ease.
I cruised at 90-95 KM/hr on the highway because of my gearing and I barely slowed anybody down. I'd pull over and they would go by on the highways, sometiems as you mentioned, 4 vehicles across.
Come speed bumps I'd bomb right by again, but once on the highway I just pulled over again and they'd go right on by without having to get off speed control. Loved it!
I'll fully admit coming back into the states I felt very restricted... =(