The vehicles' twin-turbocharged, 6.75-litre V8 engines have been modified from Bentley's Arnage R version to produce 400 hp (298 kW; 406 PS) and 616 lb⋅ft (835 N⋅m) of torque.

[1][2] For protection of the occupants, the bodywork and glass are armoured, the cabin can be sealed air-tight in case of gas attack and is also blast-resistant, and the tyres are kevlar-reinforced.

[4] The motorcade usually includes a support vehicle to carry staff and aides, which was previously a silver VW Transporter minibus, until replaced by a black Mercedes V-Class in 2019.

Until her death in 2022, she typically used the Bentleys on the rare occasions that she travelled abroad, but also used other state cars or a vehicle provided by her hosts.

Like all British state cars, the Bentleys have a mount on the roof for an illuminated coat of arms and a flag, which can be inserted from inside the vehicle.