A look at some numbers will show how strong GM’s position is. Last year, the company’s total auto sales came to 2.85 million vehicles, a figure that was up 6% year-over-year; two of GM’s full-size pickups, the Chevy Silverado and the GMC Sierra, led the American market for the sixth consecutive year, with combined sales of 940,000 units. GM is also doing well in the lower-end parts of the market, and last year sold almost 700,000 Buick and Chevy cars priced below $30,000.We’ll start with General Motors, the ...