As the OP indicated, it's not so much the dirt that gets in there, but rather the ice, snow and salt. Keeping the area clean is a pain but not a problem in the southern climes, but is a challange when it's -20. So as indicated above, cleaning it is not the solution, but only a temporary measure, especially if you drive in the northern climes everyday..... It is an unfortunate oversight by Ford that the owners are stuck with!