A new 2013 Passat sits in a bay at the Chattanooga Volkswagen plant.

Sales of the Chattanooga-made Passat were off 5.1 percent in March over year ago, but the model still posted its best first quarter ever in the U.S., officials said today.

Diesel sales of the midsize sedan hit 34 percent in March, said Jonathan Browning, Volkswagen Group of America's chief executive.

Passat sales in the month were 9,521. While that's down from a year ago, the model recorded sales of 25,909 for the first quarter, up 5.6 percent versus a year ago, according to VW.

Total VW sales in March were up 3.1 percent compared to last year to 37,707 vehicles.

It was VW's best March in the U.S. in 40 years, the company reported.

See more on auto sales in Wednesday's Time Free Press.