‘Locked’ Production Designer Grant Armstrong Tells Us How They Did It

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Written by Timothy Rawles

March 28, 2025

We gave director David Yarovesky’s Locked a so-so review when it first came out. And we still stand by that. It’s a great concept for a thriller, but it didn’t quite click into high gear even with all the talent involved. But we do recommend it when it reaches digital.

One of the best parts of the film is its technical and practical effects. From a production point of view, they had to come up with some innovative techniques. It’s filmed entirely in a fictional but functional SUV, which had to be built and modified with all the traps Bill Skarsgård encounters while being held hostage.

We know what you’re asking: How did they do it? Luckily, iHorror got to ask the production designer of Locked, Grant Armstrong, a few questions about his designs, his inspirations for the car, and how Skarsgård reacted to being stuck in what amounts to a large box during shooting.

iHorror: What were some of the challenges you faced while making “Locked”?

Grant Armstrong: car companies spend up to two years to design and build prototypes for their vehicles, and we had just 8 weeks to build two vehicles and an interior set. Therefore, time and budget constraints were always the biggest challenge.

Remember Lewis Teague’s “Cujo” in 1983, He did a similar vehicle set design technique for that movie by putting a camera in the top of the Pinto. Did you do that or was it all VFX or a practical set?

David Yarovesky wanted to make the film as realistic and believable as possible and therefore VFX was never going to be a major factor. We had a stunt vehicle built and modified for all the stunt scenes , a hero car with a finished exterior and interior and finally an interior set build where we recreated a large amount of the car park location keeping everything in camera without the need for VFX.

Locked

Did Bill Skarsgard suffer from claustrophobia during the shoot? Any funny stories about him from the set?

I talked to Bill at the premiere and he mentioned he is now triggered everytime he sees a Land Rover Defender ( the main body of the car ) and that he hated being in the car everyday for 4 weeks. Its hard not to feel claustrophobic inside any car for hours on end especially when you are 6’ 4” in height. The urine drinking was a special moment as Dave had asked us to add Surströmming (Fermented fish) to the water bottle so that it would really make Bill gag for real. 

The design of the car is pretty technological. What was your thinking behind every booby trap and hidden compartment?

It all came down to making the vehicle as believable and real as possible. I researched armoured vehicles that can be easily purchased. They look like regular vehicles but have 2” thick bullet proof glass and an armoured steel shell. Therefore this became the inspiration behind the DOLUS – a hi tech, self driving, armoured vehicle that 3 years ago you could not believe would be possible but in 2025 its a truly plausible vehicle.

What was the inspiration behind the Dolus? Was that the name of the car in that universe, or the company?

I wanted to make the DOLUS an extension of Williams character and something you would believe he would purchase.  I took inspiration from the British luxury cars such as vintage Jaguars, Rolls Royce and the Bentley. Together with the Land Rover Defender SUV silhouette it gave us a vehicle that was modern, luxurious and hi tech but did not stand out in a city centre car park. The name DOLUS came from the latin which means “fraud; deceit, especially involving or evidencing evil intent”, which was perfect for what William created. Even the logo itself was created using the Justice statue from the Old Bailey law courts in London.

What is next for you?

I’m currently waiting on a couple of shows to be greenlit but in the meantime have been working on a short film with Dr. Dre and Snoop Dog. Its been a pretty challenging time post Covid/ strikes and with streaming become more popular and cinema attendance falling. However I’m a big believer that people will always want to be entertained and who doesnt love a good story? I couldnt be more proud that our small indie film Locked made it onto the big screen.

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Timothy Rawles has been a horror fan ever since his dad bought a used hearse and drove the family to the old Orange County, California, drive-in on weekends. For more than 30 years, he has fueled that passion through horror magazines, novels, and dark rides. A journalist for over 25 years, Timothy has covered a wide range of social issues, but horror has always remained his true passion. Through iHorror, he now shares that love of the genre with fans around the world.