Stars Ewan McGregor and Jonny Lee Miller piled into an ageing BMW convertible, driving up and down the deserted A725 near Raith Junction in Lanarkshire until dawn.

Filming moved from The Orb pub earlier in nearby Bellshill, to Orbiston Junction where a mile long section of the road was closed under police supervision.

Nearby residents had no idea Hollywood A-listers were on the carriageway a few hundred metres from their doors in the dead of night.

That meant production bosses were able to keep one of the film’s new characters under wraps. The unknown female was in the driving seat as she ferried her co-stars Ewan, 45, and Jonny, 43, who play Mark ‘Rent Boy’ Renton and Simon ‘Sick Boy’ Williamson – along the carriageway.

Dressed in a mini skirt and white trainers, she laughed and joked inside the German coupe as the trio waited to film scenes.

The scene involved the three actors having a conversation while driving along in the car. It was filmed using a ‘Russian Arm’ device which allows filming from the side, front and back of a vehicle by placing the camera on an extended, moveable, arm.

Director Boyle sat in the passenger seat of a blacked-out Mercedes people carrier which drove alongside the BMW, with a monitor on his lap allowing him to see all the action.

At one point, the Oscar-winner was heard telling McGregor and Miller: “This is the real Scotland!”

McGregor sat alone in the back of the car, furiously chewing on gum and seemingly rehearsing his lines.

Close to 100 cast and crew worked through the night. Before filming began close-up car scenes were rehearsed on a site at the Bellshill Industrial Estate, while a make-up artist buzzed round the stars, fluffing up Mr Lee Miller’s hair and dabbing powder on his forehead.

The movie, loosely based on the Irvine Welsh novel Porno, is due for release in January 2017, 20 years after the original cult classic.

The Scottish Government gave the green light for filming to take place on the road which links Bellshill and East Kilbride, and is part of the £500 million M8 M73 M74 Motorway Improvements Project.

Minister for Transport & Islands, Humza Yousaf, said: “The Scottish Government is keen to promote filming at Scottish locations, given the clear economic benefits it brings to the country and the support it offers our film and tourism industries.

“It’s not every day we are approached by a production company asking to film on the trunk road network, and when we heard it was for the sequel to cult-classic Trainspotting, we were keen to make it happen.

“It takes a great deal of coordination to accommodate filming requests. We are mindful of the impact of a road closure and aim to minimise any potential disruption to road users.

“We were delighted to welcome Danny Boyle and the cast on site to film on the A725.”

Gabriel Valtueña-Ramos, General Manager of Scottish Roads Partnership, the consortium delivering the project, said: “We are delighted that we were able to accommodate the Trainspotting 2 production. It’s great to be able to say that Hollywood came to the A725. Excitement is building for the release of the film next year and we are proud to have played a small part in it.”