What have you guys done to stabalize the XL

[lincpimp]

Most likely the tires flexing. I like the elephant on stilts analogy, almost spit my coke on the monitor!

Have you set the toe, ft and rear? Also you may want to balance the wheels/tires, it will make a world of difference for handling at speed. Not sure if you want to take the tires off and tape them, might be too much work...