While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a closer look at particularly stock-shaking upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of Lear Corporation (LEA 1.30%) gained about 2% today after Deutsche Bank upgraded the auto parts giant from hold to buy.

So what: Along with the upgrade, analyst Rod Lache boosted his price target to $100 (from $95), representing about 18% worth of upside to yesterday's close. So, while contrarian traders might be turned off by Lear's price strength over the past year, Lache's call could reflect a sense on Wall Street that its growth tailwinds give it plenty of more room to run.

Now what: According to Deutsche, Lear's risk to reward trade-off is rather attractive at this point. "We've been probing the outlook for Lear's Seating business, which has been under margin pressure due to contract renewals, Europe declines, South American FX headwinds, and a challenging Seating Structures backlog," said Lache. "Our analysis suggests that this business may be set up for an inflection. At the same time, we believe that Lear's Electrical business may be able to sustain surprisingly strong margins for longer than expected." Of course, with Lear shares surging to a new 52-week high today and trading at a 15-plus P/E, I'd wait for some of the excitement to fade before buying into that bullishness.