A down on his luck middle-aged limo driver finds an unlikely ally in the famous actress he’s been chauffeuring when he tries to reunite with his family and redeem a past transgression.

This is great - I like a good healthy debate and am glad peeps are keeping it professional and mature. All the comments are very useful.
Kriss: I def. see your point about pointing up what the main character stands to lose in the logline as it makes it more compelling and makes one want to read the whole script to see what happens and whether/if the protagonist accomplishes his/her goal.
Without boring folks with some more details of the script, the event that really spurs him on to re-connect with his family is when he learns his ex-wife has had a stroke. She's not near death or anything, but the shock of the news puts a fire under his ass to go and see her, but to do that he has to get permission from "gatekeepers" = his children. Just wondering if all that information is a bit too much or even necessary in something so short as a logline....?

Steveylang: that re-working is most helpful. I've taken on the framework you came up with and re-jiggered it:

A lonely, middle-aged limo driver struggles to make amends with his estranged family, but finds an unlikely ally in one of his customers - a famous actress, who inspires in him the courage to confront his past and redeem a past transgression.

Thoughts??

If a logline reads clunky but mostly complete, then typically it can be streamlined allowing for another tidbit or 2 of detail that gives a better picture of the story. I agree that the stakes don't always need to be explicitly stated, but the better the logline the better the stakes can be inferred. Here's my attempt at making it more concise:

"A lonely limo driver struggles to make amends with his estranged family, but finds an unlikely ally in one of his customers- a famous actress who..."

It's incomplete, but now there is room to add a bit more telling detail. I would use another adjective to better describe the limo driver or perhaps the conflict with the family, but don't know enough about the story. If I knew the conflict, I might also re-frame the first part around the actual conflict.

Well course a log line needs stakes otherwise there isn't a threat to their goal. In the log line you've mentioned regarding Jaws Chief Brody has to stop the monster killing again, which ultimately would make the area a worse place. All I'm suggesting here is that to look at what the limo driver stands to lose as if he starts with nothing he has nothing to lose and I wont care if he reaches his goal.

I think the log line needs to establish a bit more of a story so we can know more about the characters. For example if a member of his family are dying and he decides to see them before they die it is a stake if he doesn't get there in time and doesn't see the family member and make amends. Is there something that makes the driver go back to his family, other than just wanting to?