I think you're assuming the car occupants would be staring directly out the vehicle's front window and only be aware of what's in the immediate front of the car. Instead, I believe they were more likely to be anticipating where their car was headed or be looking towards the Presidential limousine and how the crowd was receiving the President.
The recent evidence I've presented, based on the work of Speer and Tyler, is solid. Rather than allow it to inform your opinion about when the first shot occurred you have chosen, instead, to carry on with your own, utterly refuted theory.
The problem, for you, is that this leads to creating bizarre and disingenuous points that you will then try to argue.
For instance - you have me imagining the occupants are like mannequins, staring directly ahead as they pass through the streets of Dallas, aware of nothing else except "what's in the immediate front of the car."
Are you not embarrassed to invent such a desperate point?
Even though all 10 occupants of both vehicles make it absolutely clear they have turned off Houston St. and are travelling down Elm St, you would have us believe this is because they are "anticipating where their car was headed".
Just think about how ridiculous the point is you're making.
They are still on Houston but they think they're travelling down Elm due to 'anticipation'??
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Lady Bird Johnson says her car was "rounding a curve" at the moment of the first shot. By Z223 the VP car is well pass the curve.
So much for making bizarre points.
Now we move on to being disingenuous.
You are indeed correct, the VP car is well past the curve by z223, but what Lady Bird actually says is:
“we were rounding a curve,
going down a hill and suddenly there was a sharp loud report..."
"...suddenly in that brilliant sunshine there was a sharp rifle shot. It came, I thought, from over my right shoulder."
She is saying they were on Elm, travelling down the incline on Elm St, when the first shot occurred.
Conversely, around z160, the VP car is about halfway round the curve and nowhere near the incline going down Elm.
Clifton C. Carter said his car was "right along side of the Texas School Book Depository" when he heard the first shot. Since his statement was made in May 1964, and he morphed events, it may have been the second shot (not the first) that he heard when his car was alongside the Depository.
"At approximately 12:30 p.m., our car had just made the lefthand turn off
Houston onto Elm Street and was right along side of the Texas School
Book Depository Building when I heard a noise which sounded like a
firecracker. Special Agent Youngblood, who was seated on the righthand
side of the front seat of Vice President Johnson's car immediately turned
and pushed Vice President Johnson down and in the same motion vaulted
over the seat and covered the Vice President with his body. At that instant
Mrs. Johnson and Senator Yarborough, who were riding in the back seat
along with the Vice President, bent forward. Special Agent Youngblood's
action came immediately after the first shot and before the succeeding shots.
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I distinctly remember three shots. There was an interval of approximately
5 to 6 seconds from the first to the last shot, and the three shots were
evenly spaced."
I don't think Youngblood got over the front seat between shots 1 and 2. I think Carter filled in some of what he saw with regards to Youngblood from news reports that exaggerated Youngblood's reactions.
Why you think Carter is lying about when Youngblood got over the front seat (even though LBJ confirmed this) is bizarre and irrelevant. Instead you provide a quote stating the VP follow-up car "had just made the lefthand turn off
Houston onto Elm Street", clearly not the case at z160.
Agents Johns heard "two shots" -- so his "first" shot could have been the Z220s SBT shot (the 2nd of most LN scenarios). Agent Jacks' vehicle isn't absolutely "straightened up from making the left turn" at Z160, but he said he was looking "looking directly at the President's car at that time". So his line-of-sight was down Elm; at Z160, the vehicle Jacks was in was perpendicular to Houston and more on Elm than Houston.
The VP car is nowhere near being "straightened up from making the left turn" at z160.
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Note, Jacks stated they had already made the turn, then straightened out.
This is clearly not the case at z160.
The rest of your post has no bearing on the Speer/Tyler evidence.