A) Aptera uses about 60% less energy, generating about 60% less heat, so air cooling may work as well for it as liquid cooling does in other EVs with 60% more heat.
B) In a crash, a traditional radiator can also be damaged.
@taubmann You always have to think about the liquid polluting the environment. My Fiat 500 BEV uses the exact same coolant as as a Fiat 500 ICE.
The most delicate part of a traditional cooling system isn't centralized, it's the front-mounted radiator. The belly location you mention for Aptera IS centralized, & as you note, that's better protected...:
The belly is less likely to be punctured if you rear-end someone, or if you're rear-ended & pushed into the car ahead of you. If you're sideswiped, the belly is still likely to be okay, especially in an Aptera where it's maybe 50-50 that the front wheel &/or highly-bulging door will take the brunt of the damage.
Racing an Aptera, will still create about 60% less heat than racing any other EV that's burning about 60% more energy per mile. Rad fans do little to nothing at speed.
Every car is different, but my own BEV's rad fans only come on for a few minutes if it's over about 95F & I plug into 6.6kW L2 right when I stop & there's NO airflow. Aptera is leaning towards only HALF that heat-creating current (3.3kW), so it would likely be fine, but worst case scenario would probably only have software delay or slow down charging for a few minutes while it cools down.
EDIT: One more factor I forgot. Even with no rad fan (due to having only a radiant belly) liquid coolant can easily be chilled by the A/C fluid, even below ambient temperature, which no radiator can do on its own, even with fans. My BEV's battery coolant has A/C-chilling capacity, but it has never come on, even driving hard & then plugging straight into 6.6kW at 113F ambient.
A) Aptera uses about 60% less energy, generating about 60% less heat, so air cooling may work as well for it as liquid cooling does in other EVs with 60% more heat.
B) In a crash, a traditional radiator can also be damaged.