At the Mojave Dam the beginning of the trail is at: 34º20'47.34”N 117º13'50.77”W
For decades I parked at the dam without problems, then I started hearing of cars parked at the dam being broken in to, damaged or destroyed. If I were going to make the same hike today, I'd offer to pay a resident on Deep Creek Rd. (on the way to the dam) to park my car there. It may add a few miles to the hike, but you'll have a car to drive home at the end of the day. By the way, he dam to hot springs trail is my favorite route to get there.