I think that Oswald's response to Fritz about the station wagon proves that he didn't know anything about the station wagon that Roger Craig saw.
When Fritz mentioned "station wagon" the only station wagon that Oswald could think of was Ruth Paine's, in which she gave him driving lessons.. So, he presumed that's what Fritz was talking about. He may have figured that somebody recalled seeing him driving around in her station wagon. And so,he quickly said that it was hers and that she had nothing to do with anything. Of course, I don't believe that. I think Ruth Paine had plenty to do with the whole plot. But, I don't think it involved David Sanchez Morales or anyone else going out to Irving to borrow Ruth Paine's car. She owned a Chevrolet station wagon- not a Nash Rambler. And the idea that she owned two is ridiculous. How many people own two station wagons? They might own a station wagon and another car, but two station wagons?
And, it also tells me that the Oswald we know never got in any station wagon on 11/22. Because if he did, he surely would have known that that was what Fritz was talking about, and he would have addressed it. The fact that his mind went immediately to Ruth Paine's station wagon proves that he had no knowledge concerning any other station wagon. If he had been in a station wagon that day, he would have addressed that station wagon. But, he only knew about hers. Hers was the only station wagon in his mental universe.
Look: if Oswald knew that he was seen being picked up by a man driving a station wagon on Elm Street, and that station wagon belonged to Ruth Paine, he'd have known that an explanation was required. He'd not have responded the way he did, saying that it was Ruth Paine's station wagon but to leave her out of it. If her car was used to transport him away from Dealey Plaza after the assassination, then she was involved, and Oswald would have known that. But, if Oswald was thinking of the driving lessons she gave him and nothing more, then his response makes sense, for it was reasonable for him to ask the police to leave her out of it on that basis. But, he'd have no basis to expect the police to leave her out of it if her car was used to transport him away from Dealey Plaza that very day.
Therefore, it wasn't the Oswald we know who got into the Nash Rambler that Roger Craig saw.
Now, once you remove Oswald from the Roger Craig story, what are you left with to support the idea that he was transported out of Dealey Plaza in a private car? Nothing! There is nothing else! There is no chance that it happened with nobody seeing it. It would have happened around the same time as the Roger Craig story- give or take- and look at all the people who saw the Nash Rambler. What is it now, four?
It's crazy to just conjure up a ride for Oswald when we have no information whatsoever about any possible car, any possible driver, or any possible arrangement being made. There is nothing material, nothing concrete, nothing of substance to support the story.
And that means that it automatically defaults to the bus and cab rides. There is no evidence of anything else.
You don't like McWatters? You don't like Whaley? You don't like Bledsoe? Well, at least they're real people. (although not Bledsoe according to Backes; he thinks they invented her) Who or what is there to support the idea that Oswald was picked up in Dealey Plaza by another private driver? There is nothing! There isn't even a tiny shred of evidence to support it. There is nobody and no-thing. Nada. Zip. Zilch. Nunca. Forget it. You can't just make stuff up.