There is an accessory called 'Alloygator' but it can only have limited effect in protecting the rims. Hit a kerb hard and you're still going to damage your alloys. There are also some Pirelli tyres with a a protruding ridge around the circumference that can offer some degree of protection. But the obvious answer is not to buy a car with ridiculous oversized alloy wheels and low profile tyres and furthermore not to buy polished 'diamond cut' alloys because the lacquer clearcoating can only ever offer limited protection from stone chipping and electrolytic corrosion of the alloy from winter road salt. A lot of Porsche Macan owners are opting for 18-inch painted and lacquered alloys with 235/60 R18 fronts and 255/55 R18 rears.