I would as stated above take the woman to the bank if she decides to take the car and get a bankers draft drawn up. They won't do it unless the funds are available and it will be made out to you!!

I paid for my Esc Cos £13000 and for my Skoda £6500 with bankers draft. Just gave them the draft and drove cars away. Funds had left my bank when the wrote the draft.

They can be forged tho...