Just brainstormed this one to you after a couple of other ideas which I'll note 1 of

1) Just get her to blow you and ditch her and when the cops ask wtfhappened you just say that you guys got in a fight AND she wanted to get out. BUT after she blows you and gets out you have some buddies show up and kidknap her LFDO. But don't like kill her or some shit.

2)THIS ONE IS GREAT. OK OK You drive off to some place then you have your buddies show up and ask you like where the fuck is our money and shit. Ok ok so the girl pisses them off or some shit and they either a)stuff her in the trunk(this one is a bit brutal) or b) tie her up and blindfold her and toss her in the back of their or your car. Then you be all like guys come on man I'll have the money soon or whatever.

After that be like GUYS COME ON PUT THAT SHIT AWAY and BANG BANG BANG fake gunshots! SHE thinks you died. Then they bring the girl to some place and drop her off. Make sure the guys you get take pics or w/e.

Edit: Number 2 may leave girl traumitized for life or get you in lots of trouble. If your going to follow through on this one you need to have a false last name OR actually take a bullet.