Ferrari & JD Power

I saw the article on JD Power poll result of 51,000 people. Porsche was ranked 14 & BMW at 4th for Quality Leaders. I was surprised Audi nor M-Benz weren't ranked.

Then I realized I never seen Ferrari nor Lambo on this list for past years, too. They don't sell enough numbers of cars for this listing?

How you collect data can affect stats, so I was wondering why the newspaper don't mention the method nor explanation. I don't really know all major car makers who sells over 10,000 cars a year are even qualified to get listed in JD Power's ranking.

Do any of you know somthing on this matter?