[aerohead]

It may have been Luc Donckerwolke who penned your car. He came over to Hyundai / KIA / Genesis from being Chief of Design @ Bentley.
The final dimensions of IONIQ may have been associated with classic proportions mentioned in styling / design. Certain aesthetic considerations for the market they intend to serve and compete within.
Dr. Wolf Heinrich Hucho spoke of 'risk to sales' with respect to design considerations and specifications.
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One insightful comment:
' If we were to design the cars 100% streamlined, following all the aerodynamic principles, would not all cars look exactly alike and the designers have nothing to do?'
H. Schmude, General Motors Corporation, to Walter Korff, Lockheed Aircraft Company, SAE Congress, 1963
( duPont- General Motors Corporation, 'invented' the annual styling change, introducing design obsolescence, after dealer sales departments expressed concern that all cars were beginning to look alike, in 1927 )