I lived and worked in Shenzhen for several years, and i would not take the risk on a clear day the sunlight is too strong and the temperature inside the car may at very least affect the batteries runtime at worst it may explode.
I saw first hand the result of a cell phone exploding due to being left on the dash of a Toyota LandCruiser in Saudi, it literally destroyed the interior of the vehicle, spot of explaining to the boss eh 😛 In all seriousness a MBP has a lot more battery than a cell phone, I certainly don't leave mine in the passenger compartment here in Malaysia, for a limited time the boot/trunk should be ok as the temperature wont be amplified by the sunlight.