My 2015 Rav started showing random white etchings or marks on all of the black trim, Bumpers, wheel opening moldings and lower body trim. I tried everything to remove them but they will not come off. I believe the marks are coming from the road salt used after a snow fall. I do not let the salt on my car for very long as I clean the vehicle as soon as I can. I can temporarily cover the marks with Back to Black trim restorer but they return after the treatment has worn off. Does anyone have any idea how to remove the marks??