1) The 'spacious interior' is interesting.
2) It looks as if, in order to satisfy rollover and roof-crush requirements, that Toyota raised the rear hatch hinge mechanism above the roofline, creating an objectionable 'bulge', then to deceive the eye, installed the 'carrots. originally designed for non-laminar wing, transonic wave drag mitigation ( Airbus, Boeing, Convair, Fokker, etc. ), as a styling trick.
3) For torsional stiffness, it's important that, in a rollover, that the hatch remain closed, adding strength that would be lost, should the hatch come open.
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Next time you fly, sit behind the wings and look for these:
'anti-shock fairings'
'Flap track fairings'
'Whitcomb bodies'
'pods'
' Wing flap jacking-screw transmission housing'
'(Dietrich) K'u'chemann carrots'
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While the rear shelf will 'burst' longitudinally-attached vortices from below, the 'carrot' is positioned exactly where the 'top' of a vortice would initiate.
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At Cd 0.29, the RX 450e isn't any paragon of low drag, however, had the CFD and wind tunnel folks not 'played around' with the hatch area, range would have suffered even more.
I just wouldn't want to be a motorcyclist colliding with the back of the car.
