Retail market share is one of those metrics that tends to cut through the vagueness of pure sales-volume numbers, reflecting an automaker’s performance compared to the competition, without the distraction of fleet sales. It’s not a perfect measure of a business’s overall strength, as fleet sales can help with economies of scale and capacity utilization, but it’s one of the most accurate ways to measure the appeal of a firm’s products with real consumers. And, based on this chart of GM’s monthly retail market share (as calculated by TrueCar VP for Industry Analysis and all-round data ninja Jesse Toprak), GM’s much-vaunted Lutz-era products aren’t moving the needle with those real consumers. Emerging from bankruptcy didn’t seem to provide much of boost either. And unless drastic happens soon, GM’s battle for consumer acceptance will continue its slow but steady decline. Not good!

Hit the jump for raw data and a historical chart of GM’s non-retail market share.

Above is the raw data for GM’s retail market share, as calculated by TrueCar.

Above is GM’s overall monthly market share, from January, 1993 to March, 2011, as calculated by Morgan & Co.