Hi - I plan to put my 2010 650i in storage for the winter. I still have the run flats on it and am wondering if anyone has any opinions on whether the "Flatstoppers" are something to consider or if they are just a gimmick. If they really work, they may be worth the $250, but it seems pretty expensive to me. Do the rigid sidewalls on the run-flats provide enough support? I've provided a picture of the product below. Also, does anyone have any recommendations on what type of charger to use to keep the battery in good shape? Comments and suggestions are appreciated. Thank you.