Your "2 part body" is actually called a "composite body", invented by Jaray in the 1930s...but well done on your logic
you can basically add the drag on each separate basic shape to come up with a composite value. since the bottom is basically a brick - 0.40 - and the top is a tear drop - 0.080 - i'd say, just eyeballing proportions, that final Cd is 0.32, plus about 30 counts for wheels, and 20 counts for surface detailing...around 0.37 plus generous lift.
the wing isn't helping anything dynamically. it's too close to the body to add downforce, and downforce will just add drag. losing the wing will likely reduce drag.
i like the lotus evora greenhouse, and the way you dimpled the tiny helmets. the ridged body work will help guide streamlines...kinda like shark denticles (the new name for scales). radii are your friend. with a little streamlining, and watching the details, i'd say you could drop into the 0.2xx. you could do tuft testing on the model...If only you had a large quantity of string cut into 3" lengths. hth