Alright yeah, I found where they are. They spawn by the farmlands region, near the big crater.

https://steamproxy.net/sharedfiles/filedetails/?id=2768235459

This is nearly 74.000,-2600.000

I took this photo near the in-game map 46.000, -2600.000.
I think their spawns are probably different from Swedish machines.You may want to go to 2210.000, -3510.000. The Spetsnaz class appears there on a regular basis.You can also see Soldier-class Soviet machines in combat near -600.000, -2400,000, but I think this is less likely.

I have the same question as Iris, and also, if you start a game before the update, do the soviet machines spawn?

Where do you find those?