  The blue-shifted broad emission lines and/or broad absorption lines seen in
many luminous quasars are striking evidence for a broad line region in which
radiation driving plays an important role. We consider the case for a similar
role for radiation driving beyond the dust sublimation radius by focussing on
the infrared regime where the relationship between luminosity and the
prominence of the 3-5 micron bump may be key. To investigate this further, we
apply the 3D hydrodynamic wind model of Everett (2005) to predict the infrared
spectral energy distributions of quasars. The presence of the 3-5 micron bump
and strong, broad silicate features can be reproduced with this dynamical wind
model when radiation driving on dust is taken into account.
