To protect my alloy wheels from the ravages of winter salt and brake dust I use Poorboys Wheel Sealant, a soft paste, which is easy to apply and buff off. In addition to providing a barrier it leaves a very slick finish that makes washing off brake dust etc., an easy job. I have used it for nearly four years now on two cars and still have a little of the original half pound tub left after applying 3 coats once a year and topping up with an extra coat every 3-4 months. There is no sign of peeling or corrosion on either cars wheels, even in the area of one or two small scuffs. I have never seen the product on the high street. It is freely available from valeters/detailers suppliers. I get mine from www.polishedbliss.co.uk with whom my sole connection is one of satisfied customer. There is also lots of useful info. on their site.