You need these to load the circuit as the LEDs do not draw enough and Canbus sees the bulb as failed
http://www.halfords.com/motoring/bu...rior-lights/halfords-501-resistor-upgrade-kit
The Halfords Resistor Upgrade 501 Kit prevents error warning lights that are triggered by fitting aftermarket LEDs, such as the CANbus system alerting you that the bulb is broken. Easy to fit - this clever kit plugs into your vehicle’s bulb socket so there is no need to re-wire or solder. Ideal for high spec vehicles from brands including Audi, BMW, Mercedes and VW. ,