At The Motley Fool, we poke plenty of fun at Wall Street analysts and their endless cycle of upgrades, downgrades, and "initiating coverage at neutral." While the pinstripe-and-wingtip crowd is entitled to its opinions, we've got some pretty sharp stock pickers down here on Main Street, too. (And we're not always impressed with how Wall Street does its job.)

Given that, perhaps we shouldn't be giving virtual ink to "news" of analyst upgrades and downgrades. And we wouldn't -- if that were all we were doing. Fortunately, in "This Just In," we don't simply tell you what the analysts said. We also show you whether they know what they're talking about. To help, we've enlisted Motley Fool CAPS , our tool for rating stocks and analysts alike. With CAPS, we track the long-term performance of Wall Street's best and brightest -- and its worst and sorriest, too.

You loved the battery. Now buy the car
Yesterday, we took a look at Goldman Sachs' controversial decision to downgrade shares of A123 Systems (Nasdaq: AONE) -- just days after the battery maker inked a landmark deal with General Motors (NYSE: GM) to supply its new e-car with rechargeable batteries. A123 shareholders weren't best pleased by Goldman's action -- but just in case Goldman's right about A123 being overpriced, another analyst has stepped forward and offered a different way to play the GM deal -- by buying GM itself.

That's right. On Monday, tiny Ticonderoga Securities announced it is upgrading GM shares to buy, arguing investors have been underestimating how cost cuts will improve profits at the nation's biggest auto manufacturer. Shocked into paying attention, now, investors are applauding the move and sent GM shares sailing 2.6% higher yesterday, far ahead of the broader market's advance. But does Ticonderoga's seal of approval really merit such a response?

Let's go to the tape
Actually, no. I don't mean to sound too harsh here, folks. But the simple truth of the matter is that Ticonderoga doesn't have a very good record when it comes to picking winning stocks. At CAPS, where we've been following Ticonderoga's progress ever since it began publicly reporting its ratings last year, we've got the analyst pegged for only about 45% accuracy on the five-dozen picks it's made over the past year. Performance like this has Ticonderoga currently lagging the pack of investors we track -- and underperforming about 70% of 'em.

Nor does Ticonderoga seem to have much experience (at least, not much good experience) in the auto industry in particular. Its only recommendations here to date come from the auto parts industry, where Ticonderoga is currently 0-for-2 on its recommendations of BorgWarner (NYSE: BWA) and Genuine Parts (NYSE: GPC). Both picks have underperformed the S&P 500 since Ticonderoga made them.

Is GM really "professional grade"?
But what about GM? Even a stopped clock is right twice a day, right? Could this perhaps be the moment Ticonderoga finally calls one right? I can see why investors might think so, and why Ticonderoga might think it's stumbled upon a winner here. After all, at less than six times earnings, GM certainly looks cheap enough. That's a cheaper P/E than Ford (NYSE: F) carries, after all. Cheaper than Honda (NYSE: HMC), and way less than you'll be asked for a share of Toyota Motor (NYSE: TM)

Problem is, looks can be deceiving -- and in GM's case, do deceive. You see, while it's true General Motors reported earning nearly $10 billion over the last 12 months, very little of these supposed "earnings" came in the form of cold, hard cash. Fact is, GM actually only generated about $929 million worth of real free cash flow over the past year. So while GM bulls may trumpet the stock's value at "less than a six P/E," I look at the stock, and see it costing something more like 44 times free cash flow.

"Now wait just one cotton-pickin' minute..."
I know what you're thinking. "Aren't you the Fool who told us last year that we could "get rich from the GM IPO"? And yes, I am.

But remember, too, that when I wrote that last year, I was explaining how GM's shares were likely to rise in response to investors' mistaken perception that the company is more profitable than it truly is. How the IRS was coddling the company, and allowing it to take tax write-offs for losses incurred on its road to bankruptcy. How it could be years before the real GM began showing itself -- and how you might grab a quick "pop" on the stock, but shouldn't consider GM a long-term investment until it proved itself able to fix the problems that drove it into bankruptcy in the first place. Judging from what I see on GM's cash flow statement, however, that "fix" still hasn't yet been made.

My advice: Don't follow Ticonderoga's advice to buy GM. If you do, you just might end up stuck with a lemon.