Sergio Marchionne, CEO of Fiat, is gunning to be the world's No. 2 automaker. He has already agreed to take a 20% stake in Chrysler and now wants GM's Europe division. "I've heard him speak many times and it's clear he's got a certain target in mind of what scale is necessary to succeed," says John Bonnell, an auto industry analyst. But can Marchionne do it? He needs at least $6 billion in loans from Germany and then he'll have the politically sensitive burden of paring a workforce of more than 100,000.