"...I know it was different times back then, but why in the **** did they have the POTUS riding thru a city in an open limo like that?..."
I've read in a few books about That Day in Dallas the the SS asked President Kennedy about the bubble top. Should they put it on or leave it off. Kennedy told them to leave it off. It was a nice day and it would obscure their viw of the crowds and the crowds view of them. I saw President Johnson when he came to Memphis in 1964 or 1965 and he had the bubble top on. I believe it was the same car, too. I would have to do some digging to confirm that, though.
The vehicle that Kennedy was murdered in was never used again.