tapotti - today another thread says the mudflaps are back in stock:
Model Y Mud Flaps
I did install mine yesterday. The only strange thing was that the holes in the plastic of the wheel well did not line up well with the holes in the metal behind. so, wasnt sure if the new screws that came with the flaps would go in. but, they went in easy. Maybe the 'misalignment' is part of the design so the new screws have a tight fit! Other than that the install was quick and easy. I did turn the steering wheel slightly so the tire didnt get in my way too much.
