2006 Prius center air vents cracked??

Background:
I have a 2006 prius with almost 220K miles on it. I recently had it serviced at the local toyota dealer because I had an incident where the check engine light after I pulled over to investigate a noise coming from the rear. It sounded like it was coming from the battery vent and when I tried to restart the check engine light came on and it was disabled... anyway after an hour or so when the tow truck arrived I pushed the button to engage expecting it to roll backwards but everything came to life... so I had it towed in to have the "code" checked to so what was going on. The dealer said there was no code showing up and after 2 hours of investigating said my problem was the combo meter.... I had been having issues with it and just living with it using cell phone app for speedometer since it was intermittent.. Also perplexed as to why no code thrown or why there was a noise from the back.
OK, so I let them replace the meter... it was getting annoying since the cruise did not work at times..

Now, to the issue..
After getting the vehicle back I noticed that the passenger center air vent was cracked on the top edge... and someone had tried using glue to piece it back together. You could see something shiny in the cracks. I went back to the dealer to complain that they had broken it and not told me and the rep said the person who worked on it was not there but said they didn't do it... problem is that I didn't do it and someone tried gluing it and they had just replace the combo meter which I believe requires the top part of the dash to come out..
So, just had them replace the passenger side vent and the rep came to tell me that they did not replace the drivers side... The tech said it was worse than the passenger side and wanted to make sure they had ordered the right part... The issue here is that last night I had cleaned the inside windshield and had wiped off the dash... It was not cracked (broke into 3 pieces) last night when I cleaned it and drove it 12 miles to the dealer. I said I hadn't noticed it before... The tech said this was a "common" problem with the prius ... the sun causes the plastic to crack and the dash flexes making it work... Odd, this is a 2 inch wide piece of plastic that doesn't seem like there'd be any flexing on...
So my question (finally) is: Are there other Prius owners that have seen this type of issues with the vents cracking into multiple pieces. I'm having a hard time believing these vents cracked all by themselves especially the driver side vent that just happened to crack this morning.. Maybe this is a problem with the air vents but it seems "odd" that that 2 vents broke within the past 4 weeks....Anyone else had this happen or know someone else who has had this issue. They didn't want to replace the passenger side vent and I'm very suspicious about the driver side vent after how this has been handled by the local dealer here.

 

Arkansas doesn't get as hot as Arizona and probably not as much sun either.. I suspect they broke the passenger side when they replaced the combo meter when they took off part of the dash to reach it... The 2nd vent wasn't broke last night when I cleaned the dash... Odd coincidence that the dealer noticed it was broke this am when finished with the other side.... So waiting to see if anyone says these things crack/break all by themselves...

 

I wouldn't think so... but according to the toyota mech, these cracks were caused by the sun..
and this is what the drivers side looked like after they replaced the passenger side...