Source: TrueCar.

Like a fancy sports car getting taken out for a test drive, there's been a lot of gear shifting at TrueCar (NASDAQ:TRUE) these days. It has spent 2015 either flooring it while in reverse or shifting back into drive and putting the pedal to the metal.

One this year's wildest stocks was one of last week's biggest winners, soaring nearly 15% during the holiday-shortened trading week. There wasn't any major news out of the lead generator for the auto dealership industry. The stock merely inched higher every day last week on a steady trickle of volume.

TrueCar is in a good groove after getting obliterated earlier this year, something that may fly in the face of conventional wisdom. The stock may have more than doubled since bottoming out this summer, but the shares have still lost more than half of their value in 2015. This usually results in tax-loss selling as investors dump their biggest losers to offset taxable gains.

There was a press release issued by the company on Wednesday, offering up a rosy outlook for the auto industry, but that's not exactly news to anyone that's been following the healthy bounce in car sales this year. TrueCar -- which uses its advantageous position in the industry to offer trend forecasts -- expects total new vehicle sales including fleet deliveries to hit nearly 1.7 million units this month, 12.8% ahead of the prior year's showing.

It sees annual light vehicle sales of 17.5 million for all of 2015, a 6.1% uptick for the year. TrueCar also sees light vehicle sales growing to 18 million in 2016.

That's an encouraging forecast from a trusted source, and TrueCar should certainly cash in as it continues to gain market share in the realm of showroom referrals. However, TrueCar routinely puts out positive market data, and it hasn't typically resulted in a pop in its stock price. 

It's been a big year of highs and lows at TrueCar. It got clobbered this summer, initially after losing AutoNation (NYSE:AN) as a participating dealer in July. AutoNation had its gripes about the TrueCar model, through which it uses data from recent sales to offer haggle-free pricing on vehicles from commission-paying showrooms. Losing AutoNation wasn't pretty, and when it posted weak financial results a month later it was so bad that its CEO announced his pending resignation.

The stock began to bounce back after posting record financial results for the third quarter three months later. The news was accompanied by the announcement that former AutoTrader CEO Chip Perry would be taking the helm at TrueCar. 

It's been an odd year for TrueCar. The stock closed lower in eight of the first nine months of the year. It has posted double-digit percentage gains in each of the final three months of 2015. The end result is that the stock has soared 141% since bottoming out in August, but it's still trading 58% lower for all of 2015. 

A new CEO and healthy growth -- revenue clocked in 28% higher than a year earlier in its latest quarter -- are wooing bulls back to the stock, but TrueCar still has a long way to drive before it gets to where it used to be.