Been waxing mine when I clean and was thinking of putting some Autoglym Extra Gloss Protection on them but Gtechnic isn't a bad idea at all.
Gtechnic is a bit expensive, and as with all things, difficult to prove is value for money / effective.
I like it though so will continue with it.
I reckon the next few weekends are going to be spent buggering about cleaning and protecting for the winter, then towards the end of November putting the winter wheels on (17" 10 spoke Turismo) which will allow me to give the Black wheels a right good scrub and protect with the Wheel Armour, will also do the brake callipers at the same time.
Andy