The Road Vehicles Lighting Regulations 1989 lays out the detail of the laws regarding vehicle lighting, but because of its age it does not specifically exclude lighting in the wheelarches. However, there are some restrictions on lighting in general which you should bear in mind. Red, blue and green lighting is not permitted anywhere on the vehicle in order to prevent confusion with emergency service vehicles, lighting must be static and not flashing, and no light of any colour should be visible from the rear of the car.

If you choose to fit additional lighting to your vehicle we would always recommend ensuring it can be disabled from the driver's seat. As underbody lighting is something of a grey area there is always the risk of being stopped by the police, and being able to turn the lights off easily would be a sensible precaution.