I noticed now after this latest patch that a lot of missions now have instant, infinitely respawning enemies which makes them incredibly frustrating and IMO unplayable at least if you don't have someone else in a vehicle behind you giving you cover/back up. I just failed the mission "Four Trailers" after fighting off about 300 infinite back-up enemies that kept showing up in SUVS because they blew up the 2nd trailer right before I got to Lester's warehouse.
It's nearly impossible now not to get vehicles/trailers/etc destroyed on missions where you get chased by infinitely spawning enemies in faster vehicles. As soon as the trailer blew up I just had to ragequit the game it felt like I was playing a broken game from 1998.
Before these spawns were limited and you could pull over and fight the 5 or so SUV's that would pull up, but now they chase you forever, and the most annoying thing is as soon as you shoot one car another one immediately spawns like 20 feet in front of you out of thin air even if you're on a mountaintop in Blaine County.
It seems really unrealistic that you would have 9,9999,99999,99999X infinity enemies showing up because you stole one trailer!