The original vehicle wiring loom may not match the ISO plug used by the majority of aftermarket head unit manufacturers. Cutting the original vehicle wiring loom may invalidate the vehicle warranty. To overcome this difficulty, a Harness Adaptor will plug directly into the vehicle wiring loom and configure it to an ISO plug, therefore removing the need to cut any wiring. For further advice on which Harness Adaptor will fit your car, call our experts at your local Halfords store.