How far are you in the game?
There are 3 acts in the game and I only edited the spawns for act 3.
EDIT: Fuck me, you guys are right
At level 2 some alien cars showed up but at the higher notoriety levels only the portals appeared.
The reason why I uploaded the files was because I tested it once and then all alien vehicles did show up properl. Alright, I will fix this.
ANOTHER EDIT: Oh my fucking god, I don't believe this. Such a stupid mistake *facepalm.
So yeah, I forgot to change the act at which the grunts to appear. It appeared at act 1, this has been corrected to act 3 now, try again, I tested it and their should be plenty of aliens for you to kill now