There are no European Union rules governing your car rental rights. Therefore, Brexit will generally not have a direct impact on your car rental rights in the UK.
If the car rental company markets itself to Danish consumers, e.g. if the website language is Danish and you can pay in DKK, then Danish rules will apply.
If the car rental company does not target its marketing directly at Danish consumers, British rules will apply.
DO YOU WANT TO LODGE A COMPLAINT ABOUT A BRITISH CAR RENTAL COMPANY?
Within the EU, you have a number of extrajudicial options for lodging a complaint if, for example, a seller in another EU country disagrees that you are entitled to a refund for a product or service.
The extent to which you may exercise these options vis-à-vis UK-based companies is still subject to uncertainty. According to the UK’s former ECC office, most complaints bodies in the UK will continue to accept cases as normal. We will continuously update our information as we acquire more knowledge.
Moreover, European Consumer Centre Denmark (ECC Denmark) will still be able to assist consumers in Denmark in cases involving British companies.