I appear to have lost the small vertical flap that sits in front of the rear wheel, just on one side (RH, driver's side in UK). I saw it had come loose a couple of weeks back and pushed it back in place - it seemed to be 2 or 3 tabs that are used. I noticed today that it has fallen out completely. Firstly, does anyone know why these flaps are there? Secondly, what impact does not having it on one side have? Thirdly, is this a warranty issue or am I going to have to pay for a new one and what will it cost?