Zipcar has expanded its partnership with the Massachusetts Bay Transportation Authority by adding six new on-site vehicles and one new Zipcar location to various T stations in the Boston area, the company said Thursday.It is. But this isn’t a yard sale nor an eviction. No T-shirt uniformed street teams promoting Blackberrys to government workers. No ad-hoc charity lovers selling Krispy Kreme donut boxes for $5 in front of the Metro escalators. No sidewalk floormat signs that appeared until DCRA put the kibosh on them. Enter Zipcar, the popular car sharing service that has its DC office at 717 D St, NW, and what we think is the most unorthodox attention getter we’ve seen downtown. Unorthodox enough that we call it news.