Sales Day Notebook: GM Share falls to all time low.

With GM reporting March sales early in the day, and the industry racking up its 19th consecutive month of year-over-year gains, one fact that largely slipped under the radar yesterday was that General Motors grabbed it's lowest share of the U.S. market ever: 16.5%.

The previous low of 16.6% was set in March 2011. Buick and Cadillac - which have been growth brands for the auto maker both underperformed the market, as did a number of the company's high-volume CUVs.

Mid-size cars were the largest selling segment for the second consecutive month, and grabbed an 11-year high share of 23.5%.

Prior to February CUVs had been the market's top-selling segment for 28 months, dating back to month immediately following the close of Cash-for-Clunkers.

Nissan had its best volume sales and daily sales in March, but only its second-best market share, falling less than a tenth of a share point short of the company's benhmrk 9.75% take in March 2011.

Honda’s share dropped to 9.1% in March from 9.6% in February and 10.8% a year ago. Its first-quarter share of 9.3% was its lowest for the period since 2007.

Every one of Honda' cars recorded a double-digit shortfall.

Honda truck increased 9.5% thanks to a 35.2% surge of CR-V sales. Excluding CR-V, Honda’s truck sales declined 2.1% from last year.

Mitsubishi’s sales were down 8.7% despite healthy gains by the Galant midsize sedan and the Outlander Sport small CUV.

U.S. Light Vehicles set a new record for fuel efficiency on the WardsAuto Fuel Efficiency Index for the third consecutive month.

Six companies, including GM, reached all-time highs on the WardsAuto Fuel Efficiency Index in March.

Ford Fiesta daily sales dropped 35.9% from year-ago. But the comparison comes against the vehicle's best-ever daily rate of 362 units. this March's 232 DSR is actually the new Fiesta's fifth best daily rate since its June 2010 launch.

Toyota sold 200,000 light vehicles for the first time since the August 2009 Cash-for-Clunkers sales spike.