Hard on the wheels of Ford's (NYSE:F) better-than-expected, if still worse than last year, Q1 2007 earnings report, its Detroit rival General Motors (NYSE:GM) gears up to report its own first-quarter earnings tomorrow.

After the news comes out, we'll have time aplenty to dissect it. But in these few hours before we begin obsessing over GM's short-term progress, let's take a moment to review what investors think about it as a long-term investment. Our tool in this endeavor: Motley Fool CAPS, where we poll more than 28,000 investors for their views on well over 4,000 companies, GM among them. Here's what Fools have to say about the company.

Up or down?
More than 1,500 investors have submitted opinions on GM. The verdict: Generally bad.

Barely 34% of CAPS investors think GM will outperform the market, a nearly 2-to-1 margin of pessimism. Worse, among our very best investors, the CAPS All-Stars, GM's approval rating stalls and drops rapidly to sub-20%. No surprise here: GM gets just one star out of a possible five on CAPS. (Probably only because we don't have a zero-star option.)

Then again, that's not uncommon in Detroit:

Major Auto Manufacturers group

CAPS rating

Toyota (NYSE:TM)

*****

Honda (NYSE:HMC)

*****

Tata Motors (NYSE:TTM)

*****

Fiat (NYSE:FIA)

****

DaimlerChrysler (NYSE:DCX)

*

Ford (NYSE:F)

*

General Motors

*

Wall Street vs. Main Street
Over on Wall Street, the professionals lean toward the opinions of our best investors. Only one of the four Wall Street-ers tracked on CAPS gives GM the thumbs-up -- 25% approval. Funny, that. Over the last 52 weeks, GM has in fact outperformed the S&P 500 by better than 21 percentage points.

Bull pitch
While admitting GM's well-known problems with high labor costs and cash flow "issues," bulls still see a future for America's largest car company. Citing "better product," progress in negotiations with the UAW, and -- from a valuation perspective -- a single-digit P/E ratio, bulls like GM's chances, or at least the chances of the shares, at this level. Particular shining lights include: "They are number one in China and are becoming profitable in Europe again."

Bear pitch
The top-rated bear pitch on CAPS goes something like this: "GM is saddled with terrible cost issues and terrible products that cost too much to be taken seriously." Concluding: "The law of comparative advantage means that there is no future for Detroit autos. Don't even begin to think about a buyout. That isn't even worth laughing about. Who would buy a company that makes a bad product and is saddled with irreparable labor problems that are causing its downfall."

Who said that?
To learn the identities of the wise Fools who penned these thoughts, and explore the plethora of additional financial data we've put together on the company, just click here.

Fool contributor Rich Smith does not own shares of any company named above. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked 170th out of more than 28,000 raters.