First, the noise when you open the door. You've made sure it's not
correlated with the interior lights, right?

Yea. The car has daytime running lights that won't shut off but otherwise,
nothing is on when I hear the noise (besides the system).

What happens when you wiggle
the tweeters in place?

Doesn't seem to have any effect.

Go over bumps?

Makes no difference.

What about the midrange speakers?

They work perfectly. I have to say, I'm still having a ****ty time getting
these speakers to sound the way I want them to though.

Has he checked those, to make sure they're not grounding out either?

Yupp, they've got lots of clearence.