If our Jeep is in both of our names can my Gf stop me from driving it? it was paid for in cash and we owe nothing on it.?

If it's in your name also (big mistake on her part if you are not married), she cannot stop you from driving it. And if the bills, that you "helped" with, are yours also (rent, food, utilities), then you are NOT "helping" someone else with their bills, you are being responsible for your own share of them. It's a BIG mistake for unmarried couples to have large purchases put in both names.

It doesn't matter where the money came from to pay for it, if you are on the title then you are allowed to drive it anytime you want.

If it's in both names both owners are entitled to drive it and the other can't stop them. Who paid for it doesn't matter.

If you are not married and she is mad at you, she can report it stolen. Doesn't matter how much you have given to her, if the title is in her name then it belongs to her. If the title is in your name then it belongs to you. If you are not married and you live together this tells me that you both intend to keep your separate belongings. It seems like you two are getting a divorce before you are even married. Happens everyday to couples not married and living in fornication together.

Whoever's name is on the title can drive it. If only one person's name is on the title, the other person can drive it with the signer's permission.