I subscribe to Consumer Reports and have for years, on line. I often read their reviews before going shopping. I do the annual surveys they request on-line. My responses has always been highly favorable for my 2016 MS (as well as my wife's Subaru). They do not use third partys for their surveys. Since they do not accept advertising, their opinions are mostly unbiased. I always take their recommendations with a grain of salt because the items they consider most important are not necessarily the same as mine. I remember when they first reviewed the MS and gave it a score of 103 out of a possible 100. They have since had to change their rating process.
I also remember when they first tested the M3 and could not recommend it because of a breaking issue. Tesla was not aware of the issue but was able to reproduce it and was able to upgrade the software over a weekend. CR then changed their recommendation.
I think is is probably accurate that many of the issues identified have been corrected. I guess it is also possible that some people are submitted FUD information to CR in their surveys, but I think you have to be a subscriber to get the questionnaire. You do then identify things that you own and that you are willing to answer questions about. The next year they remember what items you reviewed and ask if you are willing to update information on those product.