The splash guards do not keep the side of the car clean. Mine turns salt white too (upstate, NY). What they do amazingly well is to stop the wheel discharge stream from directly splashing onto and across the sides of the front doors. Without the guards, there is a distinct fan shaped mud or salt pattern on both front doors, possibly an erosion issue long term. Otherwise, it's just more of mess (without guards) compared to "normal" dirt / mud / salt coatings with the guards.
Agree on a right angle ratchet driver. Years back at the lab, many techs had these relatively expensive little kits, I think "Chapman" tool sets in yellow fold open plastic boxes. A quick google shows similar right angle ratchets now for $8!
I have a big floor jack, and almost just took the rear wheels off to get more room this time. Then I realized that my stubby with reversible tips comes apart. I used a large plastic trim removal tool to press the end part with the bit into the screw by pressing against the tire. Then, I used a little 3/8 inch open end wrench to turn it, gently pulling trim the trim tool against the tire as the screw went in. I worked surprising well.
Also, it is probably best to avoid the power driver on these. The screw heads are relatively soft and get marked up pretty easy if the bit slips out. I used the driver gently on the outer ones, but it really takes a lot of care not to leave marks. The threads are relatively course, it is almost as easy to just put them in with a regular screw driver.