"Django Unchained" actress Daniele Watts and her boyfriend Brian Lucas wrote the all-time worst apology letter for their lewd conduct arrest ... barely saying sorry, and instead blaming the incident on OTHER racist cops.
As part of the deal they took in May -- when they pled no contest to disturbing the peace after allegedly having sex in a car -- the couple had to write the apology letter to the arresting officers ... who she accused of racism.
In the letter, Watts says recent stories of biased policing played a role in her behavior ... and says she got defensive because one of the officers quipped, "Thank you for bringing up the race card. I never hear that."
The couple also wrote a letter to employees in the office building where their car was parked during the alleged hookup. In a totally passive aggressive tone they said, "We are truly sorry that our expression of love caused such a disturbance to your lives that you felt it was threatening enough to warrant police involvement."