What's the difference in these two products? I've been using meguiars extra, which is marketed as a cleaner/degreaser, not a wheel cleaner. It's safe on rubber, plastic, vinyl, etc. I use this product to clean the white lettering on my tires. What's stopping me from using it on my rims as a wheel cleaner also? I mean why should I spend money on another product? Other products like simple green and castrol cleaner/degreaser's (diluted) are safe on plastic and other materials so couldn't these products also be used as wheel cleaners? Even though these products are being marketed as two different things, can't they perform the same function to a point?