I left a Glock on the dash of my car last August, a long story....
We live way out in the country up a dirt road at the base of a mountain.
As I was coming home from my dance recital one afternoon I noticed a big fat groundhog up in one of my peach trees munching away on a peach.
I stopped the car, drew my Glock 33 and knocked him out with one shot.
I placed the pistol on the dash then hurriedly retrieved the dead whistle pig and took it in the house to show my wife. They are tasty and tender when cooked in a pressure cooker with lots of veggies. Groundhogs, not wives. Actually, wives are good for (and good at) other things.
I forgot all about my Glock until several days later. When I opened the car door it was like a blast furnace. The force nearly knocked me down.
The Glock had melted and run down off the dash and dripped onto the carpet. All I had was 3 puddles and a handful of bullets. As hot as it was I have no idea why the rounds did not ignite and explode.
I would post a picture but my camera was in the car as well and it is now 2 puddles in the back floorboard.
I dug the bullets out of the black goo, cleaned them up and fired them in my new Glock with no problems. I still have the brass and can post a picture of them from my new camera if anyone does not believe me.
So, ammo is OK but Glocks will melt.
I think the only true sentence you said in that post was "I was coming home from my dance recital"
*The highest temperature inside a car I've been able to find anyone willing to claim was 180F.
*The autoignition temperature of smokeless powder is around 320F
*The temperature rating of most automotive wiring is 257F. I don't know how far above that you can go before running into problems...
*The melt-point of nylon 6 and nylon 6,6, two polymers commonly used in the firearms industry, are 437F and 509F respectively.
Now, I'm not saying you're full of ****, but I want to know why Glocks aren't made out of the same polymer they used to manufacture the carpet of your vehicle!
At 4:00 or thereabouts in the second video, the guide rod melted and fell out of the gun. The gun kept running without it.
OP, I think the Glock will be fine in the car. The car will fall apart before the Glock. But be careful with Kydex and other thermoplastic holsters.
For what it's worth, the G17 (and I think the G19) passed a NATO test that required it to function after a 24-hour heat-soak at 70C/158F. The rest of the Glocks are made with the same polymers; I don't see a problem.