The brushed finish on my Kirkham is/was the easiest, least worrisome finish I can imagine taking care of.
I love the look of the painted cars, but I'd always worry about door dings and paint chips. Never in issue with the brushed aluminum. If it ever got a little grungy looking, I'd take a red 3M pad to it, and in an hour or two, it looked brand new. I only did this every couple of years, and usually only after fixing a dent and cleaning off some
oil or grease.