Updated results posted. And there's now a separate results page for each model and its competitors--the single table of all results has gotten way too big.
Good question--but the answer is a bit complicated. Minor routine maintenance such as fluid changes is in the list of items that should not be reported. Brakes used to be in this list, but people wanted to report them. So now brakes are reported, and are posted to the repair histories on the site, but are not included in the analysis.
We recently started asking participants to report major preventative maintenance, like timing belts and water pumps. I have not yet decided how these might be included in the stats. Currently, timing belt and water pump failures before 70,000 miles are included in the stats, but those after this point are not, in an attempt to equalize results between timing belt- and timing chain-equipped cars.
We're going to start providing new stats for the odds of requiring no repairs and the odds of getting a lemon. These require larger sample sizes, so additional participants would be helpful.
For the details, and to sign up if you haven't already: