Investors should expect mixed headlines relating to U.S. car sales for may of 2012.  While the pace is certainly enough to keep sales for the entire year above 14 million, it has fallen off from earlier in the year.

The SAAR in April dropped from above 14 million in earlier months this year to 13.8 million in May.  For Sirius XM (NASDAQ:SIRI) investors the month of May also produces slightly mixed results.  Whether we like it or not Sirius XM's stock is sensitive to the headlines of the auto sector.

Despite auto sales in May being above 1,330,000, they were shy of the nearly 1.4 million the street was expecting.  Year over year numbers look great, but it is the expectations of the here and now that define the sentiment.

For Sirius XM any number above about 1.1 million allows the company to produce decent metrics that will typically meet expectations.  Given that fact, sales of 1.33 million are good news for satellite radio, despite the issue of sales being below expectations.

Ironically, the tempered enthusiasm for auto sales may be a blessing in disguise for the satellite radio provider by easing the pressures to increase the current 1.5 million in subscriber guidance any further.  As has been noted many times before, Sirius XM trades at a premium in a time when stocks that trade in premiums are not appreciated.  Managing expectations, and thus the premium is likely a very healthy thing for Sirius XM right now.