Overall temperature isn’t 90C but your lunch could be in contact with those temperatures:

https://www.clickorlando.com/news/2019/09/26/heres-how-hot-t...

“In a locked vehicle, a dark dashboard, steering wheel or seat can often reach temperature ranges of 180 - 200 degrees F, which then warms the air trapped inside a vehicle.” 194F is 90C.

And that’s Florida, other parts of the globe have higher outdoor temperatures which result in higher internal temperatures.