Some GM Data:
 

Don't know about other nameplates...


1:50pm 05/02/06 GM GM April U.S. Saturn sales rise 14.1% - MarketWatch.com
1:49pm 05/02/06 GM GM April U.S. Hummer sales soar 230.7% to 5,413 - MarketWatch.com
1:49pm 05/02/06 GM GM April U.S. Buick sales fall 17.6% - MarketWatch.com
1:50pm 05/02/06 GM GM April U.S. Pontiac sales fall 20.9% - MarketWatch.com
1:48pm 05/02/06 GM GM April U.S. truck sales rise 1.7% to 210,801 - MarketWatch.com
1:47pm 05/02/06 GM GM April U.S. sales fall 7.1% to 345,404 units - MarketWatch.com
1:48pm 05/02/06 GM GM April U.S. car sales fall 18.1% to 134,603 - MarketWatch.com