You do not have this right. The 2009 Murano was the safest of the nine
SUVs in a particular test group. IIHS did not "certified it as the
safest mid-sized SUV." It was classified as a "Top Safety Pick" but it
is not unique in this classification among mid-sized SUVs. Even this
rating is based on IIHS's very specific tests and has nothing to do
with real world performance. It is often the case that IIHS "Top
Safety Picks" don't have particularly good injury loss ratings (see
http://www.iihs.org/research/hldi/composite_cls.aspx?cls=8 ).

See http://www.iihs.org/ratings/summary.aspx?class=55 . It appears to
me that there were at least 7 mid-sized SUVs that were rated better
than the Murano by IIHS. In fact it was listed 8th out of 9 mid-sized
SUVs that qualified as "Top Safety Picks.":

The important thing to remember is that the IIHS works for the
insurance industry, not consumers. They are more than willing to try
and force you to pay for marginally effective (and often ineffective)
safety devices if they feel it may save their Customers (the Insurance
Industry) a few dollars. As a result of the IIHS efforts Consumers are
being forced to spend billions on marginally effective safety devices.

Ed