With a name like Dr. Tranny's Instant Shudder Fix, the first thing I though of was 'snake oil', but the stuff actually worked. My '95 was shuddering or bucking at between 40 and 50 mph, about the spot where the overdrive was kicking in. I remembered seeing it discussed on the Pontiac Bonneville Club list when I had my Bonne and decided to give it a try. A two-ounce tube did the trick and as the name suggests, it was pretty much instantaneous. The bucking sensation isn't completely gone, but it's at a livable level. It also seems to be helping my fuel consumption slightly.