Didn't fit? that'* probably because they actually take 880'* I dont' even know what H11'* are? give me a minute and I'll find out. It'* very doubtful they'd just up and change bulbs like that after like 18 years or so (including intoduction of the SSE back in 89? used 880'* for the foglamp bulbs)
O.K this is a photo of an "H11"
very similar to the 881 curved base. I believ H11 are used in high end luxury cars Like BMW, Mecedes and such. The bulb looks more like an headlamp bulb more than a foglamp one, I'm pretty sure pontiac didn't go this route just for one year. (I do believe GM only uses the 880 series type bulb 880,881,893 ect. I could be wrong though,