I would say TLDs are very influential.
The Page Rank is high with nissan.com due to its lawsuit with Nissan Motors. They even have a link at the top of their page with information about the lawsuit.
Many tech articles have been written about www.nissan.com. This is more a study about Page Rank, Public Relations and the Streisand Effect than anything.
Their ad [1] says it explicitly: "webmasters rank better in Google with backlinks on Nissan.com". That seem to be against the webmaster guidelines, no?
0. http://www.nissan.com/backlinks.php 1. http://www.nissan.com/images/Backlink.jpg
people search for [nissan.com], so that domain has navigational search demand, which is very likely a factor for google.
people link to nissan.com (yes, they do https://www.google.com/search?q=link%3Awww.nissan.com&pw...) without even checking if it's the right domain (and sometimes out of other reasons than we think, i.e. lawsuits
(CMS also tend to convert every .com pseudo urls into an link, so this is also a factor)
people tend to click on official looking search results, .com looks official.
google prefers what people search, link, click on. so (sadly) .com matters.