(IMO) I think it is XGF at the wheel of the Jeep, captured in the surveillance shots, rather than CC. But, if not, finding her prints on the Jeep would not be unexpected. The way I read the affidavit, it seems that the XGF borrowed the Jeep from the friend, telling him that she needed it for her own use. I don't think she told him that she wanted to borrow his Jeep to lend to her friend (CC). Then, in the course of having the Jeep at her disposal, she claimed to have let CC use it briefly (possibly to run those errands for the XGF that CC referred to).
As far as when the owner got his Jeep back from XGF, I don't know. I'm sure if he didn't get it back first, then LE took it directly from XGF for forensic processing.
Can you imagine driving that Jeep now, after this horrible murder? It will be gawked at by millions, like the white Isuzu Trooper that O.J. drove on the freeway enroute to turn himself in for questioning! (From then on, whenever I saw a white Trooper, I was reminded of O.J.!)
For the past week, I have driven by a house in my neighborhood that has a ladder leaning against it, reaching to upper story window. Every time I passed it, I thought about the Lindbergh kidnapping!
(I have a bad case of "W.sleuthitis".