<human>: Can you give me the gist of the text in a nutshell?

I've known my friend Sarah for almost ten years. She's one of my more responsible friends, very trustworthy, and we currently work together every weekend. I love her and I'd do anything for her. Key word, HER.

She has horrible taste in men, and her current bf (a fucking legit criminal who has done time in jail) got his third DUI in her truck, crashed it, and it was seized by the state. Fortunately she had another car, however the car is partially her ex-husband's, and is due to be repossessed any time now. She is saving up to file bankruptcy due to their divorce, and as such, cannot afford a car at the moment. 

Here's where my problem comes in. After much arguing and crying and suggestions of every possible alternative, she has decided that we need to switch cars until she can file bankruptcy and buy another car, so hers doesn't get repossessed. 

I would give her my car in a heartbeat (if the switch would even work - I mean, her ex knows where I live and work!!!). But not with drunkie felon bf around, not to mention his two toddlers messing up my car. I don't trust her decisions with him in the picture. I have told her exactly this and she just brushes it off.

How do I explain to her that I will absolutely not trade cars with her, and still preserve our friendship and working relationship?
<bot>: Friend is dating shitbag who totaled her car, now she wants to borrow mine. How to say oh hell no bitch without her killing me.