Thanks to excellent support from this forum, I was able to post an updated result for the Smart ForTwo today at TrueDelta.com. As promised, this forum has been credited with making the result possible in today's press release.
Three months ago we posted a result for the ForTwo based on a limited amount of data. We have much more data this time around--66 owners responding for an average of three months--and the posted repair rate is quite a bit higher than last time, 90 successful repair trips per 100 cars per year--or a bit under one trip per car per year. The average for a 2008 model is around 60. So the number for the Smart is worse than average, but the difference isn't huge, less than 1/3 of a repair per car per year.
Unlike other reliability studies, this one updates every three months. So we'll have another result in November, with a preview for participants in October. Given the healthy sample size, I wouldn't expect a large change, but one is always possible.
The more participants we have, the more precise the result, so hopefully more owners will join.
Full set of results:
TrueDelta Vehicle Reliability Survey results