Mercedes a Luxury Biofuel Ride

I've been considering buying a 1970s Mercedes 300D to run on biodiesel.  I don't want to spend much and would use it as a commuter or to simply show off.  I love the 70s sedan styling, leather interior, the wood panel dash and the chrome bumpers.  These vehicles have also been known to possess drivers with Grey Poupon accents - one of life's finer pleasures, of course. 

photo from RanWhenParked