The party continues for Johnny Manziel ... because the QB just arrived at Coachella. 

Seriously. 

Manziel just got to the music festival along with his pal Ryan Silverstein -- aka OVO Ryan -- the same guy he was with during that bad car crash on the Sunset Strip this past weekend. 

Ryan is currently being investigated for hit and run. Manziel told police he was a passenger in the car. Johnny has not been accused of any wrongdoing. 

Several people in Johnny's life have begged and pleaded with the QB to seek treatment -- including his past 2 agents -- but Johnny has refused. 

Instead, he's at a music festival in the middle of the California desert.