Corporate executives, especially those running the Big Three, do indeed make most of their money through investments rather than salary, as they are multimillionaires prior to taking the CEO job. I imagine that $200,000 should be enough for anyone, especially when you take into consideration that their housing and transportation needs are already taken care of by the company in addition to salary.
Why the Chrysler CEO needs more security than any other passenger flying first class, I do not know. Perhaps he just does not want to announce the time of his flight so as to avoid having a mike stuck under his nose.