I noticed the black limo appears quite frequently throughout the film.

The film executives arrive in it before their meeting with Kesher (and Kesher goes on to smash it up).
The limo that Diane/Camilla rides in is black both to the party and at the beginning of the film when the accident happens.

But very strangely, Betty's parents travel in the black limo after seeing her off at the airport. Is there any significance here, or just Diane mixing things up in her dream? After all, her parents' grins are quite deadly, which perhaps is making the point that this is a dream, or that their hopes for their daughter are ultimately to be quashed...

Another thing... who's the guy that's loitering around Diane and the hitman with a hotdog? (I think it's a hotdog, he's eating something anyway). He follows them right of frame, but says nothing.

Also what's going on with Angelo Badalamenti's character spitting the Espresso out? Is that just another way of saying Diane will never get the part?