so far,for a 'practical' road-going car,the streamline half-body is 'best' for low drag.
It's sloped-back 'BUG' nose,with its generous plan curvature naturally forms a splitter and with the flat belly gets all the air moving around the body at similar velocity and pressure netting low lift and drag.
The modern splitter nose dates to the mid-1930s,with the research of Fachsenfeld.It prevents any air to be directed under the vehicle,gets the forward stagnation point very low (very good for low drag),directs air to the cooling system inlet,kicks the remainder around or over with full attachment.
Since mass-produced cars are different from the 'ideal' form,we attempt to capture as much benefit we can from the splittered BUG nose,while permitting 'real' day to day driving on real roads and driveways without tearing anything off the car.
Low-drag concept cars ate combining active suspension and active aerodynamics to reach a more 'ideal' nose which can survive the rigors of real driving.
SAE recommends a clear 16-degree line of sight 'RAMP' angle from the front tire/road interface,looking forward and up in order to not destroy body parts.