I had just recently took a few hard drives with the Bonneville in the hills between Malibu and the Valley in California. Extremely hard turns of mountain winding road ranging from 10 mph to 45 mph (max speed in the corners) and a max of 50 mph on the straights with the GXP'* acceleration.
To follow the road I went on, go here:
from:CA-23/Westlake Blvd to:Mulholland Hwy to:34.044837,-118.93507 - Google Maps
First time I drove, I took it a bit easier since I had my fiance, her sister, and my cousin in the car, but I went back for a trip alone.
I baked my R1 rotors with Friction Master ceramics to a crisp toward the end of that road on the dowhill toward pacific coast highway to the point where I could barely stop because they were too hot and had to downshift to keep from going too fast. Of course, that was when I was alone in the car. Damn that was a LOT of fun.
However, driving those two trips made me realize how badly the car sways and how limited the handling is as a result, so I went out to autozone and bought some off-the-shelf Energy Suspension Polyurethane sway bar bushings and got those installed. What an AMAZING difference. Its absolutely unbelievable. The stock rubbers are worthless, and I'm not even exaggerating.
Installation for the front end links was a bit of a pain, but it was doable with a quick trick. The front bolts are a tad bit too short, so you have to leave the stock one on one side of the car while both wheels are off the ground, and jack up the hub on the other side of the car in order to compress the end links to get the nut on the bolt.
The part numbers are:
Front end link: 1 5/8" part 9.8120R $18.99
Front bushing: 1 1/8" part 9.5164R $20.99
Rear end link: 1 5/8" part 9.8120R $18.99
Rear bushing: 7/8" part 9.5158R $20.99
Best money I've spent on this car so far.
Note: make sure to grease the bushings and end links, and don't over-tighten the end links. I over-tightened mine in the front and forgot to grease them, and they squeak a bit when going over speed bumps. The rears are fine though.