You've got three scenes. In the each scene is one car - the same car, and the same actors (two of them).

The car appears in three different locations - parked each time. The three different locations are evident:

1. Forest - day
2. Airport - night
3. Car park - day

Do you use an INT or EXT as your slug?

In each scene you are inside the car, with the characters talking.

As the location is important - would you full slug the location, and then mini the car or full slug the car? It's like a mini establishing shot?

Appreciate any thought on this.

I guess write two full slugs.

EXT. FOREST - DAY

the car is parked on the side rode.

INT. CAR - DAY

Gary and Greg drink coffee.

Hope this helps,
Gabe

I think in each case you first use an ext. slug to establish the location, like:

EXT. FOREST - DAY

A CAR sits parked along a trail.

INT. CAR - DAY

Bill and Bob stare at the dashboard.

Well, that's a little rough, but you get the gist.  Sounds like you're asking if you can use just one slug for the whole scene and I don't think that's gonna work.

Yeah, I agree with the chaps above, Simon.

I would use an EXT. scene and establish the location and then move to an INT scene in the car. I would not use a mini slug in this circumstance but that's me.

Use a mini slug to showcase either the switching of locations or the inside of the car... If the scene hasn't ended, don't end it.  Most people will assume a scene has ended when they see the location change -- this isn't always true.   But when people write with so many scene headers what's one to think?

Mini Slugs are a great way to keep your scenes going without taking up too much space in the process.

EXT. FOREST - DAY

A white, beat to hell four door rolls to a stop.

CAR

Ray Jay Willson turns to Jay Ray Willson in the passenger seat - he draws a pistol from his inner coat pocket.

--

The above tells us where we are/location (forest) and how we're getting there/what we're following (car).

The below tells us we've shifted perspective, without a tacky cam angle or an intrusive slug, (into the car) and who's inside,  (Ray Jay and Jay Ray)

You can, if you want, put a INT. CAR, but that is one step to a full on slug.  

A) You don't have to worry about an Orphan with the lone CAR by itself on one line, cos' you didn't have any parents before it.  

B) It frees up the monotony of your page.

--

But it's merely a suggestion... Do what you feel is best for you and what reads the best for you.  

Thanks guys - that's great - whichever way the location gets established first, and then we go to the car.

Thanks for the feedback.

Simon