Kurt Busch – My ex-girlfriend is a trained assassin

Patricia Driscoll (L) – trained assassin

Kurt Busch's ex-girlfriend is in court to get a restraining order against him – but the NASCAR driver is fighting back with what he says is proof she's a certified badass who couldn't possibly be afraid of him.

Patricia Driscoll testified in a Dover, Delaware court Tuesday about Kurt's alleged attack on her after one of his races in September. As we've reported … Driscoll claims he choked her inside his motorcoach.

But sources close to Busch tell TMZ Sports his legal team has submitted a YouTube video of Driscoll as evidence. The video entitled "Pocket Commando" — was posted earlier this year, and shows her at a gun range, showing off marksman skills and talking about the company she owns … Frontline Defense Systems.

Driscoll calls herself a "commando mommy" on the video … which we're told was shot and edited to pitch her as a reality TV star.

We're told Busch's attorneys will argue that Driscoll is a "trained assassin" who would have no reason to fear Busch. In fact, during Tuesday's hearing Busch's attorneys called her a "mercenary" out to ruin his career. Busch adamantly denies the attack.

It's likely the video will be played in court on Wednesday. TMZ