I've been known to do a few of those things, including taking the wheels off and cleaning the suspension components. That decisions was actually influenced by some oil that dripped down there, so it was nice to get both sides perfectly clean front/back. And I got to learn a bit about the components/design behind the wheels.
I do like a spotless interior. Sounds silly to most, but when I step into the M3, I want it to look and feel like a brand new car. That means a quick vacuum after every trip, if necessary.
OP, have you taken a shot at paint correction/compounding? That's a great way to put an OCD eye-for-detail to great use