I agree. Got mine back today after the dealer install and I couldn't believe the difference. The old yellowed units really stod out. You had to really look to see the line of the new guards. Really cleaned up the car. Nice to see that Porsche takes care of these little details.

 

With the new car, I'm using the cleaner spray they offer, which happens to not be Plexus. (I'm gathering that possibly something in the Plexus spray could lead to the yellowing?). So far 3months+, 2600miles its still clear!

Actually on my other cars I never had an issue with the nose sections changing, just the areas behind the wheels. Could very well be just the nature-of-the-beast with road "stuff", and cleaning it a bit more regularly.......