Possibly the most innocent way to improve drag on a car is remove door handle bulges... But strangely nobody has solved it enough for there to be an obviously accepted answer..
Tesla has done this three different ways and it still causes some confusion.
Model S - self presenting handles.
Pros: Easy to understand, Easy to use.
Cons: expensive parts, complex, breaks, doesn't work without power.
Model X - Push buttons.
Pros - simple mechanic.
Cons - require hard push for safety, can be confusing, door response can hit you and stop requiring repeats. Requires power.
Model 3 - push-pull levers.
Pros - simple mechanic
Cons - two step, not immediately obvious, harder with full hands.
What else is possible?
A spring loaded cover
Pros: no wrong way to push it.
Cons: may gather dirt?,
Self covered handle
As opposed to motorizing the handle... The aero pressure is what here's the handle only when car is in motion.
Pros: looks 'normal', aero only when needed.
Cons: ???
Vertical door seam handle
A scooped handle hidden behind the back edge of the door.
Pros: no exposed parts.
Cons: visually confusing
What else have you seen? What else can you think of? What problems can you see?
Eazz.