Lockdown Won't Spawn

Okay, I know this was a common problem back in the day with the OG version of the game, which I totally forgot about when I started playing the Remastered SR3 for the first time. I'm kicking myself now for forgetting I needed to save a Lockdown for that Vehicle Theft task in the Saints Book. Anyway, I am sort of locked in because STAG is in town, and I spent over an hour at 3, 4, and 5 shields desperately trying to steal one.

I know I could wait until the end of the game when STAG is gone, and I think there is a trick for choosing SWAT homies later in the game, which I seem to remember working to one degree or another with this.

If possible, though, I would prefer to find a way to get one now, as I like to get all the side quests done before moving the story forward. If there is no way, I might just load up a save I have which is about 2 or missions before this save, and just go back in time, as it were, save a Lockdown to my garage, and just move forward from that point. Again, I would prefer not to wait or to go in my little gamer time machine of possible.