  We consider the leading and sub-leading twist $T$-odd and even contributions
to the $\cos 2\phi$ azimuthal asymmetry in unpolarized dilepton production in
Drell-Yan Scattering. We estimate the contributions' effects at $500 {\rm
GeV}$, $ 50 {\rm GeV}$, and $25 {\rm GeV}$ energies in the framework of the
parton model using a quark diquark-spectator model of the nucleon to
approximate the soft contributions.
