Chevrolet was down 2%, Cadillac down 29%, Buick down 3% and GM
C down 0.1%.Retail sales -- the most profitable kind for the industry -- rose 3% for the month, according to GM
.Edmunds.com had projected an overall GM
sales decline of 2%, while Kelley Blue Book had projected a decline of 3%.GM
discounts rose 14% to an average of $3,909 per vehicle, according to TrueCar. The Silverado is GM
's most popular and most important vehicle.Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.