When the fire department is helping the police secure the body, the turntable ladder is registered in the city Gelsenkirchen but has markings of the city of Siegburg on the roof. Both would not be the case for a truck used by the Essen Fire Department. Also, the truck is too old for official use in such a large city.
When Mick is driving through Essen in the opening scene, a newsagent's with a WestLotto sign is visible, in the design that was current at the filming time--not in 1994, when it's set.