RE: Temperature limits for Airtronics 2.4ghz receivers?
A plane in the car and worse yet the trunk is a bad idea in this heat.
The RX mostlikely being unpowered will survive OK although I wouldn't subject mine to it.
I'd be more concerned for the airframe warping in some manner.
Try to avoid this at all cost, or keep the car absolutely in the shade.
MIke R