See the Full Video of Britney Spears' DUI Arrest

Britney Spears was busted for DUI back in March, and now we get to see how the whole thing played out.

TMZ has obtained the full dashcam video of Britney's arrest -- from the moment cops hit the lights to pull her over ... which she took her 3 minutes to do!

The pop star's out of frame for most of the footage, but you can hear her going through the field sobriety test -- including when cops cuffed her -- and seemingly blowing into a breathalyzer as she insists she's not drunk.

At one point, she tells the officers she wants to drive home, but they let her know she can't. You can hear Britney respond ... "Yes, I can drive home. Why are you telling me that?"