I'm going to get my car back!!!!!!!!! The dealership called. It's either the fuel pump or the fuel pressure regulator, and they pretty much have to fix the regulator to determine if it's the problem. But it's the least expensive to fix, so we're going to run with that. It will be ready around mid-day tomorrow. If it were the fuel pump, you'd think it would just die at some point and that would be it, so I'm betting the regulator will fix it. If not, at least we'll know what comes next.
Happy news! Let's hope this is the start of a nice little string of happy things.