The Specs on the Solstice GXP are:
5 x 110mm bolt pattern
55mm Offset
18" x 8" size
1. Open deck led
2. Remove plastic covers (2)
3. Remove screws (2)
4. With a small screw driver pry on front of tail light to remove light from retaining pins
5. Remove bulbs
General Motors discontinued the entire Pontiac nameplate a few years ago, in a "trimming down" of the corporation.