The red path in that image is a backstage road, if I'm not mistaken?
I believe the bus loop you're referring to is the one by the main parking garages? That bus loop used to include uber and pickup/drop-off, but a few years ago they changed it to limit congestion. The new pickup/drop off is at one of the parking garages (did my best to show it in the picture below). For that reason, I'd recommend walking to the Hard Rock Hotel (green line below), and having them pick up your son there.
The only caveat is that you'll want to be at the hotel before their car arrives, as the hotel doesn't want tons of cars sitting there waiting for guests.
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