As an aside as it is not in production, the closest car design to a teardrop
may be the Mitsubishi iMiEV Sport concept car that has been kicking round
for 3 or 4 years on the auto show circuit:
Initial concept, very teardrop-like
First concept car, pretty close to initial concept:
Latest iteration, less teardrop-like; steeper front end, shorter wheel base.
Due I guess to real world considerations:
Why the teardrop shape? See
http://ecomodder.com/forum/43045-post1.html