Updated August 6, 2023
Parking for the monorail is a good question.
At the north end, parking in the Sahara garages is free and the monorail station is right there, so that’s easy and no different than it's always been.
In the middle, you can park at Westgate for free, unless there’s a big event and a charge to self-park. Otherwise, you'll have to pay to park at a hotel-casino if you're catching the monorail from center Strip; Harrah's/LINQ, Flamingo, and Horseshoe/Paris all charge to self-park and valet park.
Parking at the south end has a few more options. You could park at OYO, but you have to cross Tropicana Avenue at a crosswalk, unless you want to walk to the corner at the Strip and take the pedestrian overpass.
You could park at Tropicana, but doing so, you’re expected to patronize the place, so to be proper, you’d have to walk in, do a little something there, then cross on the overpass and head to the monorail.
Otherwise, you have to pay to park at the MGM Grand in order to pay to ride the monorail.