So, I have had my MS since mid-November 2012, and have received an average amount of looks here and there (mostly from people familiar with Tesla). I really don't think most folks notice the MS as anything out of the ordinary, compared to say a Fisker, Karma... (which is fine by me). Plus where I live, seeing luxury cars, exotics, etc is a fairly common thing.
However, now that I have my California 'Access Ok - Clean Air Vehicle' (carpool / HOV lane access sticker) on my MS, I am getting people literally driving around my car with curiosity. Of course here in insanely crowded Southern California, having an 'Access Ok - California Clean Air Vehicel' sticker on your car, is about the equivalent to Willy Wonka's Golden-Ticket! Then I realize, Tesla has never done any advertising to the general public, and not everyone is a tec-head / car-geek (like myself), and are unaware of a luxury car that is also zero-emissions that can qualify for the program.
Ironically, this is the last thing I thought would draw the most attention to an MS, however, I guess when suffering from 'bumper-to-bumper syndrome' on a daily bases (that most suffer from where I live), I too would be curious how such a nice looking luxury vehicel gets legal single-occupency access to the HOV lanes. ;-)