I'd really like to keep my 235/40 fronts, but they rub on the lower lip of the duct where it meets the wheel arch. It's been difficult to blow/roll the arch liner and the duct together, so I'm going to 3d print an insert for the duct that replaces the lower edge of it and allows more clearance. In the future I might close off the arch aperture altogether and print a part that feeds some flexible hose that cools the inside of the brakes directly (exdos-stylee).
That plus it's a chance to learn a few new skills during the cold winter months and I'm a sucker for a stupid project.