dont forget the airport is still in use, and the runway they use for the main straight, is the main active runway, so they cannot put anything permanent there, no lines that sort of thing, and they have to clean up all the camera gear, and barricades when they have finished filming to allow normal aircraft operations to resume. i know because i fly out of that airport! its Camden airfield south west of sydney,
actually about a 2 months ago, the strip was closed for filming, and a aircraft in the area had a door come off inflight,, the pilot then declared an emergency, and proceeded to land on the runway in use for filming! unfortunately due to flying with no door, the wind noise meant he couldn't hear air traffic control instruction about the closed runway, and he proceeded to make a perfect emergency landing on the runway! and managed to avoid hitting all the barricades, and camera crews! apparently the stig was just turning off the strip as he landed!
i cant wait to see if they include any of that drama in an episode!!
though the practice of closing the main runway at an active aerodrome has pissed off quite a few in the aviation community here..
especially when there is a good closed down airport in St Marys, in Sydneys north. which has 3 sealed runways, and plenty of options for test tracks and tests. the old Schofields airport still exists even though it has been closed now for nearly 10 yrs!