Q to all tech nerds in the thread, please hear me out (I can ramble on, sometimes)...
General understanding is that the cooling for ICE (water/oil/charge) will be less than previous regs and the cooling for battery pack and MGU will be more than previous regs.
And we have seen how in 2026 cars, the packaging tightness is extreme (esp McLaren/AstonMartin), which hints that a lot of cooling has moved centerline across the paddock, and the 'thin sidepods' must have only 1 or 2 'big heat exchangers'. We also saw pictures of the centerline air-to-air IC in RedBull's case (which is one of the "big" ones, apart from the water+oil ones) ; reducing the need for large sidepods.
Now coming to my Q - we have seen the 'no undercut' teardrop sidepod with a suspicious 'bottom panel of the teardrop' that isn't blue painted. Could this be 'two storeys' with a roof separating the blue and grey zones, but sharing the same main sidepod inlet at the top/front ? What if all the heat exchangers are in the top storey, and what's held in the grey zone is just 'pressurized ram air' ? (the air wouldn't weigh anything and maintaining the teardrop shape all the way down helps push out the front wheel wake perhaps without too much cost of drag penalty). The higher pressure in this 'mezzanine' area needn't have an outlet and would help push the floor down even more (apart from underfloor suction).
Just a wild thought. Feel free to call me stupid
