With hundreds of partnerships ranging from farmers markets to art festivals and pride parades, Zipcar, Inc. has long used sponsorship to demonstrate community involvement and support its brand DNA.And the car share company continues to expand its portfolio. Zipcar this summer ran a promotion with GLAAD around which it made a $1 donation to the nonprofit for every hour one of 27 co-branded cars were on the road.Zipcar also is expanding its partnerships with IKEA and Target Corp. The company recen...