What wouldn't make sense is that Travis would sell the BMW to a person with no job, no means to pay rent, and has to go back home to her parents because she can't afford to live in AZ on her own. This is the main theory about why he wouldn't sell it to her before it got ruined.
The mess about her having to "give the infiniti back to the bank" is suspicious for where it appears in her journal in March 2008. If she was cleaning it to give it back to the bank in March, how does it wind up in Yreka? (and cleaning it, Jodi? With your messyself. I doubt you cared if it was clean to be repossessed.) She still owned it when she rented the car for the murder trip. She got that tow thing to tow the Infiniti. She probably expected her mom to drive one of the vehicles back while she drove the truck back to the rental house. But her mom abandoned her, and so she wound up having to tow the BMW after driving herself to pick up the uhaul. She should have left it at the Uhaul to pick up later, but my theory is she got the bright idea to tow it, so she didn't have to go back and probably so she could learn how to hook up the infiniti.
Do you agree, though, that Travis voluntarily selling the BMW to a broke person prior to the car's destruction is nonsensical? He knows she can't pay her bills. He knows she's always borrowing from him. So what would be his expectation that she'd actually pay for the BMW? He had no choice but to trust that arrangement once the car was destroyed--but before it was destroyed? He had no reason to.
I think she added the Infiniti going back to the bank info into her journal after her talks with Flores. IDK why she put it in there, but otherwise, why did the car never go back to the bank? Who stepped in and paid for it not to go back at a time when she owed for the BMW?
And seriously, if Travis knows the infiniti is being repossessed, why in the world would he sell her a car, so he'd be in the same boat as the people who loaned her for the infiniti? He'd be in worse shape because he wouldn't be able to repossess, not all the way to Yreka, surely.
JMO.