The industry as a whole is trending strongly upward at the end of a long summer of brisk car sales, but the luxury segment in particular is showing positive returns. Leading the charge are Cadillac and BMW, up 37.8 percent and 45.7 percent, respectively.

For General Motors' [NYSE:GM] luxury brand, Cadillac, continuing strong sales of the ATS (3,380 units) and XTS (3,533 units), plus the still-strong SRX (7,211 units) drove most of the gains. The soon-to-be-replaced CTS fell 22.5 percent in August to 3,980 units sold, while the Escalade line saw mixed results: the base model fell 4.8 percent to 1,203 units; the ESV rose 3.4 percent to 767 units; and the EXT fell 1.1 percent to 181 units. Cadillac's August 2013 sales total was 20,255, a 37.8 percent increase.

At BMW, sales of passenger cars nearly doubled against August 2012, up 96.4 percent to 19,483 vehicles. Wrapping in SUVs, which were down 27.1 percent to 5,040 units, the total brand was up 45.7 percent in August, selling a total of 24,523 vehicles. The brand's sales leader was the 3-Series, accounting for nearly half of total volume on a 66.9 percent increase to 10,357. The next-best seller in August was the 5-Series at 4,359 units, a gain of 158.2 percent over last August. The X3, X5, and X6 all saw dips of 20-30 percent, while the new X1, BMW's smallest utility, climbed 295.5 percent to 2,278 units.

BMW and Cadillac weren't the only brands to impress in August, however, with the Lexus brand up 16.7 percent over last year, selling a total of 16,978 vehicles, the ES sedan leading the way at 7,628. Audi rose 21.5 percent to a total of 14,005 vehicles, with a strong diesel mix of 25.6 percent in the Q7 SUV. Mercedes-Benz gained 15.8 percent in August, selling a total of 27,144 vehicles (24,761 of which were Mercedes-Benz brand cars), with the C Class leading the Benz ranks at 6,701 units.

Weaker performances at Acura (up 9 percent to 17,051 vehicles), Infiniti (up 6.5 percent to 11,884 vehicles), and Chrysler (up 2 percent to 28,678) still represent solid improvements, especially as the economy continues to struggle globally.

The smaller-scale luxury and performance carmakers also saw gains, for the most part, with Porsche up 10 percent to a total of 3,327 vehicles sold in August; Jaguar-Land Rover selling 6,661 across its two brands, a 40 percent gain; and Lincoln up 0.6 percent to 8,192 vehicles.

Volvo was the odd man out last month, declining 5.7 percent against last August and 12.7 percent against July 2013. Total sales of 5,518 leave the brand just about on par with Mitsubishi, a worrying factoid.

For a more detailed look at the full industry's sales tally for August, visit The Car Connection's August 2013 sales report, and for a peek into the world of plug-in electric car sales, visit Green Car Reports.