I believe you're correct, Eric. There's always a Free Enterprise bus waiting next to La Salle street in the AM, waiting to take people to Oglivie (presumably for a Metra -> Metra morning commute). I know that if I was commuting like that and the price was good, I'd consider it over the CTA "L" since it can presumably get you there curb-to-curb.
Free Enterprise's website indicates they do a lot of charter business & airport shuttles. That's probably where most of their money is made. My observation is that the La Salle - Oglivie shuttle I see usually has a fair amount of people on it (and if it hasn't yet arrived, there's a line waiting) and the buses look to be clean and well-maintained.
That old car might be worth money!