Rear spoiler dull/faded

So I guess this is called the spoiler and on my 2010 Prius has become dull/faded. I don't know what remedy to do to address this issue. The edges are still glossy-like but I don't know what causes this dullness. I thought maybe it is similar to the headlights where you can use toothpaste or wax to return the shininess, but it doesn't work for this.

I also have so other cosmetic issues with my 2010 Prius, in that in January 2021 I noticed some snowflake patterns/cracking in the paint on the right and left corners of the roof just above the driver and passenger side, which I am told it is due to the clear coat. Since it was a small area at the time and not worth the cost to address such a small area, I decided to leave it alone. Unfortunately, I can tell that the area got bigger/more noticeable as well as is reaching everywhere like the back of the roof towards the antenna as well as on several doors just below the window. Clearly it looks like it is going to be a more expensive job as probably the whole vehicle should get painted/new clear coat.

I live in Southern California and unfortunately my car has been parked outside, so I am assuming that the exposure to the elements contributed to these issues. Furthermore, I feel that as a Prius owner, there is this need to be environmentally conscious so I don't wash my car as often as I should, especially since California has been in a drought over the past 12 years. In addition, I am that weird/crazy person who is out putting some soap/washing the car in the rain, since the rain does all that rinsing/removing dirt and that soapy water. Anyway, I wish that more people would do that when it rains or if Toyota could put that commercial back on the air again especially with California's drought.