Also....I have a gut feeling, but i'm probably wrong...but I want to call it just in case...
The last scene will be a mirror of this scene...
https://www.youtube.com/watch?v=2r5aUrAnFy0
Except reversed, like the actual scene. He'll aim that
M80 down upon those advancing sirens. Hank closing in. He looks down. And starts firing.
Either he'll be taken down, or it'll cut to black right there. But honestly, since these guys want to give us a good solid ending, I say they'll show him getting ripped apart.
Probably flashbacks of every great moment in his life. And all the people....as well as Jesse. Who he hopefully didn't kill already.