I can see why Quartzsite is so popular!
All along Plomosa road there are turn offs you can park in. It's pretty rocky, so go slow, but I managed to find a semi private spot nestled behind some trees. Mostly quiet, though occasionally heard coyotes. Only 6 miles from town, mostly gas stations and RV campsites, but there was some cool little shops across from the Pilot gas station. Pretty dark night sky, especially considering how close it is to town.