The BMW Britney Spears was driving when she was arrested on suspicion of DUI last night has been picked up from the impound lot, TMZ has learned.

TMZ obtained photos of the car being driven -- not by Britney -- from the lot after it was held overnight.

We broke the story ... Britney was pulled over by California Highway Patrol officers around 9:30 PM Wednesday in Westlake Village, California, not far from her home. We're told she was alone in the car when officers initiated the stop.

Our sources said she was transported to a hospital so officers could draw her blood to determine her blood alcohol content. We were told she didn't sustain any injuries, and the hospital visit was strictly for BAC testing purposes.

After the hospital visit, Britney was booked at the Ventura County Jail around 3 AM Thursday. She was released a few hours later, around 6 AM.

She's due in court on May 4.