Generally I drive my E320 to work, but will take the Boxster when I head to classes at the university (no hang-tag parking passes anymore). On occasion I'll drive the Boxster to work and do not receive any odd glances as I arrive at the office before majority of the staff does.
I have received the "You have a Mercedes
and a Porsche? You must have money!" line before.
My Mercedes was a cheap cash buy, is 18 years old, and isn't pristine (but still looks nice). My Boxster cost less than a new Corolla, but I'm sure they wouldn't bat an eye if I told them I picked up a new econobox. Ha.