You need to read the "you know you're an ecomodder when..." thread.
EDIT - Hit post too quick. You could experiment with a much smaller mirror, maybe a bike one if you have to have one legally (we do), or one of those van type ones which have a hollow "arm" segment and smaller mirror - I'm thinking old style Opel Corsavan/Combo style ones.
Something like this
with smaller glass ?
EDIT 2 - or something like
these, I've never found them here (UK) though.