Not my first mod but one I saw on here recently and thought looked pretty cool, red tinted rear lights: It was pretty easy to do. I bought a sheet of red window tinting film from Amazon for £8.49 which arrived today and got stuck in. I drew a template on each segment of light with a marker on clear plastic (cut up freezer bag!) and transferred it to the film. I cut it out and then used two pieces of tape to peel off the backing and then floated it into place with soapy water and then squeegeed them into place with an old microfibre cloth. I have doubts that it'll pass it's nexy MOT but I think it looks pretty good ! Total job time about 20 minutes.