I didn't read the whole thread yet due to the backlash I was sure to see after such an ending.
And I thought that the first parts were not ambiguous enough... I have been naive
I liked it but I really don't want the "it was all a dream ending". I am interested in the interpretations that will be discussed on this forum, but I will try ignore this one: that would undo the work and intentions of many on sets (and I guess that's part of the reason Fenn was unhappy with her role at some point) and anyway the final sequence seems to show that there is more than that (Audrey waking up, Sarah calling Laura and Carrie screaming...).
This makes me glad that Mulholland Drive was a movie and not a series. I would have hated to get attached to characters that would never have existed.
I must also say that I am not conmfortable with retconning the end of FWWM given how powerful the final sequence of Laura and Cooper in the Red Room.
This post makes me seem more unhappy than I am: I am not but I don't like what it could be interpreted as. I think the upcoming book of Frost will explain Briggs' plan.
My interpretation at the moment (based mostly on the Pilot, FWWM and TMP and season 3 since I believe them to be what Lynch was the most familiar with when he wrote the revival):
At the moment, I believe that the dreamer is Judy (aka the Mother aka Experiment aka Jumping Man, inhabiting Sarah), some sort of lovecraftian horror like Azatoth, the whole universe being its dream, we all inhabit and it began to fall appart when Cooper exited the Lodge. Jeffries tried to use the powers of the Lodge to defeat Judy once he discovered what it was at the meeting but failed.
The Fireman converted MIKE to his cause, but the arm's doppelganger was still on BOB's side and tried to stop Cooper in Part 3.
BOB tried to be Laura and become the nuclei of this world but by puting on MIKE's ring she prevented it.
Cooper used the powers of the Lodge to save Laura from her fate, she vanished from existence and entered another world (kinda like the explanation linked by the search for the zone website:
https://www.youtube.com/watch?v=L5hLj8E4rTE) and was reincarnated as Carrie Page. It destroyed what was schemed by Judy, Laura being a creation of the Fireman (cf Part
made for this purpose ("Laura is the one"). Judy wanted its creations to gorge themselves on those living in the world that opened to her with the Nuclear bomb.
Diane waited for Cooper at the curtain call when he exited the red room and followed the giant's indications, he entered the new Laura's dimension where they became Richard and Linda. Diane stayed in the previous world and was replaced by her tulpa who interpreted it as being another Cooper who raped her and the real one became Naido who is central for Cooper to use his powers (the superimposed face of Cooper appeared when she became Diane back).
The world manufactured by saving Laura was supposed to be free of Judy's monsters but, as showed by Sarah calling Laura, it can not be completely vanquished.
I also believe that Cooper and his doppelgager both had a similar goal but not for the same reasons (if the doppelganger/shadow self won, he would have fused with Laura's essence after using the power near Jack Rabbit's palace,. To use it one of the 2 Coopers must die and absorb the other). Jeffries actually did work with both.