The trailers can blow up?
I know I did that mission last night before the patch, and the spawns were seemingly infinite then. (I took out at least 7 SUV's)
But I just waited until I had a few seconds between spawns to hook up the trailer and took off. Like all trailer missions, they shoot at the trailer but it does no damage to me. Acts as a nice bullet blocker.
I did that mission solo a week or so ago, and I got a trailer jammed up and could not move it, so I had to get out and start defending against the SUVs of thugs that kept coming. It seemed like the supply of SUVs was infinite back then, so I don't know if this mission has changed.
I was actually having a lot of fun killing each new wave of one or two SUVs as they came up to me, but soon the street was littered with SUVs plus a few blown-up cars that got caught in the crossfire, and the game eventually crashed, probably because the total number of vehicles and dead guys overran some database memory allocation.