[RooRoobird20]

The route was changed at the last minute and the decision to put the limo top down was a last minute decision.

This was 54 years ago in Dallas Texas, during a more innocent time and in a city that loved JFK.

[RummyChick]

Not a jfk murder historian but have seen claims SS Lawson approved the change in route on this 11-18

[plain talk]

The route was changed at the last minute

Not sure what you mean by last minute. The final detailed route was published three days ahead of the JFK trip in the Nov 19 Dallas newspaper

[iowamark]

The route was changed at the last minute and the decision to put the limo top down was a last minute decision.

Nonsense. JFK typically used the open car, on an announced parade route, on political trips.