I have the SS louvers in my car. They don't come off for cleaning unless you want to retape them, but honestly the windows don't need to be cleaned much. I've had them on over a year, the only cleaning they've gotten is a bit of runoff soap and water from when I wash the car, and my windows still look fine. They aren't spotless, but its nothing you can notice from inside the car. Not a big deal at all unless you're OCD.
The nice thing about the SS ones is that very little dirt gets in there anyway. I've only had to pull out the occasional leaf.