To make life easy the best thing to do is take the wheels off and clean them properly then polish and protect them with a sealant. After that they can be cleaned very easily for months!
I've tried many different ways and products and have settled on the following.
Remove wheels and spray with Autosmart tardis. Leave to dwel for 10 minutes then agitate and rinse off.
This will remove tree sap, tar and other spots and marks. This can also be used to remove any old sticky strips from previous wheel balance weights.
Sometimes a second application and microfibre cloth is needed.
New repeat with Iron X product. Personally I use Gyeon Q2M Iron.
This will remove metal contamination. But be warned it smells and will leave red residue on the ground if not rinsed away.
Rinse thouroughly and dry well.
Polish wheels. In truth there will be very little (read zero) difference between different polishes.
2 coats for good measure.
Seal wheels with a good wheel sealant. I find Poorboys to be very very good. Easily 6 months protection and stands up well to everything I've put it through.
After that you will find the wheels very easy to clean. I can normally clean them pretty well simply with the power hose. But to get them clean you can use a number of wheel cleaners as long as they dont strip the protection off. A very under rated product is 3M wheel and tyre cleaner. Very cheap and does a great job.
I used that for a while but I'm now trying Wolf's Clean and coat nano wheel cleaner. Its also very good.
Spray on, agitate and rinse off. With many wheel designs you can see alot of the alloy behind the spokes so if you have these I'd also advise the use a wheel wooly to properly clean in behind without the need to remove the wheels.
That way they are protected and easy to clean
