Clearly it was a slow day for new car press releases so some hack was asked to whip up a space filler article.., Ironically, if you follow the link to 'research the 3 series', the reliability rating is 5 greens for 2006/7 and 4 greens for the 2008, the last year for which they have data. Hardly matches with the article does it?
The term 'reliability' is not a quantative term in this article, but there is also no definition of the meaning and no source for the basis of the opinion. So it's pretty worthless.
It would be fascinating if manufacturers actually released warranty and other statistics that would allow an objective reliability evaluation - but I guess there's zero chance of such closely guarded secrets ever coming out. And, of course, the attitude of the manufacturer in the face of failures is important. In that respect, BMW does seem to have stepped up done the right thing with the 335i issues.