What happened Shares of online car-shopping service TrueCar (NASDAQ: TRUE) were down sharply on Tuesday, after the company posted a wider third-quarter loss and scaled back its full-year guidance. As of noon EST, TrueCar's shares were trading at $11.10, down 32% from Monday's closing price. Image source: TrueCar. So what TrueCar's third-quarter result was a mixed bag. While the total number of vehicles purchased via its service rose 15% from the year-ago quarter, its average fee per sale dropped to $306 from $319. Likewise, while its total number of new-car dealer partners rose 16%, the average revenue realized by TrueCar per dealer fell 5% to $5,319. The results were exacerbated by changes at TrueCar's most important referral partner, USAA, which revamped its website in ways that reduced the amount of traffic referred to TrueCar. CEO Chip Perry expressed optimism that the situation with USAA would improve, but it may not fully recover. Now what As a result of the changes at USAA, TrueCar also lowered its full-year guidance around sales and revenue. It still expects both to increase from 2016 levels, but it had previously guided to significantly higher results. Things aren't looking as rosy for TrueCar as they were in the first half of 2017. 10 stocks we like better than TrueCarWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and TrueCar wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of November 6, 2017John Rosevear has no position in any of the stocks mentioned. The Motley Fool recommends TrueCar. The Motley Fool has a disclosure policy.