Blac Chyna, Rob Kardashian Back in L.A. After Marathon Bentley Ride

Rob Kardashian and Blac Chyna are back in L.A. County ... 2,800 mile road trip in just 3 days.

Rob and Chyna were spotted in Beverly Hills Monday morning, which means Rob has driven virtually nonstop the entire weekend.

TMZ broke the story, Chyna was arrested Friday at Austin International Airport for being drunk and disorderly. She was also busted for possession of ecstasy.

Rob literally jumped in his Bentley minutes after Chyna's arrest, drove for more than 20 hours to Austin, and then turned around with his prize and returned to L.A.

12:00 PM PST -- Looks like Rob dropped Chyna off at a laser specialist to get her "Future" tattoo removed.