A taxi! Once you have that number of people, Mears or similar is not cost effective because you are paying per-person. Have the front desk call you a cab that will fit six (they'll send a mini-van-type vehicle) and you'll get door-to-door service at its least expensive! It's also NO problem picking up a cab for the return trip -- if there isn't a large vehicle already waiting in the pick-up line, a driver will radio for one for you.