The use of police uniforms, police cars and weapons in filming can be tricky, as it can be perceived as an imitation of real law enforcement officers and can confuse the public. To ensure that you can use these items legally and safely, there are a number of steps to take:

1. Mention the use of weapons, uniforms and/or police cars in your request so that the police division concerned can give its opinion and authorisation for their use in this respect.
2. If the police agree, you can hire uniforms, cars or weapons from a private hire company.

Following this:

1. Inform the public: when filming in public places, make sure that passers-by know that you are filming and that the police equipment used is not real.
2. Safety first: when using weapons, even dummy weapons, safety must always be the top priority. Follow the instructions of the weapons advisor and make sure that no unintentional danger arises during filming.

Remember that it is essential to comply with all relevant laws and regulations to avoid unwanted legal complications. It is essential to consult professionals and obtain authorisation from the relevant authorities to ensure that the film project is a success and is carried out in complete safety.