Bought a mini this weekend along with some mothers mag polish. Worked more than fine for my polished wheels which took a beating over the winter with salt/sand everywhere.
No signs of wear, red dust, etc. Just took it apart and washed it with liquid dish soap and water, put it up to dry. If it only lasts for 4 uses before I have to pitch it, that'd be just fine. I'm done polishing anything as large as wheels by hand. Just not worth the time vs. spending a few bucks.