scrub back of wheels and fender liner?
 

Does anyone take their wheels off and clean the backside of the wheels and the fender liner? I had planned to do this every year but I've gotten lazy and never done this. Is this necessary or is this a waste of time?

I reach in as far as I can (which is pretty far with the Rays) every time I wash. You can only get about 75% because of the brakes, but if you do it every week, they stay clean.

The fender wells aren't a huge deal on the Z becasue they're pretty tight, but cleaning and dressing them makes a huge difference on a car where they're real visible. I just use my wash mitt (last thing I do) and then when they're dry spray some cheap foaming tire wet on them. Really improves the look on my truck-not so noticeable on the Z.

I just did this. I jacked the car up, removed the wheels, cleaned the wheelwells with APC and a brush. Applied plastic protectant to the plastic. Used Wheel Armor to wax the calipers and the front and back side of the wheels. If you have the time go for it.

I do it every wash. Part of detailing the whole car.

i confess to removing whells to clean& polish with Rimwax every couple of months, keeps them pristine.

Just reach in as far as ican on the wheels. When I wash the car reach in and wipe down the the wheel wells.