I have the S, and the only weight that is a perfect "fit" is the one for $199 on ebay. Not paying THAT. I have the coiled one for like, $30. It is not pretty, but effective. I failed to add..in addition to adding the weight on AFTER I've started driving and AFTER I've activated AP, I also either adjust the volume via scroll wheel or do a random tug once every 5-6 mins. Randomly. Combo of THAT is allowing me to not get any nags at all. Keep in mind Im only doing that on longer highway trips on the interstate as thats really the only time I use AP anyways for the most part. Other times I simply prefer driving the car mysel