Dirt beneath temperature display 2014 Prius Three (IMAGE)

Are you sure that is not just a plastic covering the lens to prevent scratches?
That covering may just peel off.

Disassembly to get behind the lens....I don't think is possible without major skill and maybe some luck.

 

This thread about car stereo upgrading includes all the directions for removing all of the plastic pieces around that display. It can be done without tools; I've done it myself. Once you have it disassembled, that display will be bare, and you can look for some way to remove that plastic cover. It looks like someone spilled something on the dash and some liquid entered behind the glass. Disassembly will let you clean out any gunk that's back there, but I do not know if you can clean behind that display.

I also attached a drawing which shows the disassembly. It's easy to do, but I don't know how to get behind the display unit.

 

Yeah, it looks almost like air bubbles that can sometimes exist if there is a plastic sticker on top.

I'd carefully look to see if there is anything that looks like an edge that can be pealed off.
Unfortunately, I'm not sure you can get behind that piece.

 

That's what I was thinking but I would think you see it also on the black surround too. I think, unfortunately, it might be surface deformities from using the wrong kind of cleaning agent. What I don't see is dirt.

 

I could be wrong.
Was hoping for an easy solution.

If you enlarge the photo, there are some spots in the black frame. However I can't tell if it's dust or dirt on top the black or underneath.

 

Let me be clear in case there is any confusion in that drawing: Those two plastic pieces are removed by pulling straight UP. Not "away from dashboard," but straight UP.

Don't use a screwdriver to pry them out; you'll scratch up the plastic. If you have strong fingernails, that should be fine. Once you get just a little bit of the first piece to loosen, it's all straightforward and it will all come out.