Penske Automotive Group (NYSE:PAG) -- formerly United Auto Group -- reported a solid 10.5% increase in earnings, to $0.42 a share. This doesn't include discontinued operations from both periods. That's a nice, steady drive forward rather than a blowout, which could cause overheating.

Each of its business lines performed well, and all saw same-store revenue increase. As a whole, the company had an 8.5% jump.

I like its brand mix, which relied on the popular BMW, Toyota/Lexus (NYSE:TM), and Honda/Acura (NYSE:HMC) for 57% of its sales in its latest quarter. By contrast, the poorly performing Ford (NYSE:F) and General Motors (NYSE:GM) made up just 12%.

Gross margin did fall slightly to 14.8%, from 15.4%, but this was due in part to the sharp rise in sales of used vehicles. At Penske, these have lower margins. Sonic Automotive (NYSE:SAH), another automotive dealership, also saw an increased reliance on used cars, but they're a higher-margin business for Sonic. Gross margin could see an uptick in the future, as it has renovated many of its service and parts stations, which generate huge margins -- 56.2% in the latest quarter.

There's no great secret to its success. The company is diversified geographically, and that paid off with same-store revenue increasing 22.8% outside the U.S. This compares to a 2.5% increase in the U.S. This quarter, sales outside the States made up 37% of the company's top line.

Having a strong international operation protects the company when there's a downturn in one country or region. Lithia Motors (NYSE:LAD), by contrast, has heavy exposure to the domestic market. It relies on the more popular models, which are taking market share away from unpopular domestic vehicles. This is like other dealerships that realized the profitability of offering finance and insurance, which are enormously profitable. The markup for financing is incredible -- people forget they could get a better rate at a bank, and the convenience of doing everything under one roof gets them every time.

Its brands and presence outside the U.S. should continue to benefit the company. At a trailing P/E of 16, investors may well find the shares too hard to pass up -- without the haggling.

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Fool contributor Larry Rothman is happy to receive feedback, and promises to read it when not being wrestled by his three children. He doesn't have any positions in the companies mentioned. The Fool has a disclosure policy.