Freddie Fields, Barbra's agent (not manager) is the man who founded ICM was and is one of the toughest guys in Hollywood. I guarantee you he was no **** around Ray Stark. And if he did get Babs a $5,000 a week raise, in 1966 dollars, that's a "paltry" $30,103.09 in today's money (using the Consumer Price Index, 5,000 in total worth has the buying power today of 79,000.00).
As for the limo, I heard this entire story from people who work for him and since we never spoke in anything but hushed tones, I may have heard it wrong.
Although there was a lengthy artcle about this in the last year or two and I remember reading it there also and saying to myself, "wow, the tales were true."
http://www.broadwayworld.com/board/readmessage.cfm?thread=972787#3631451
http://www.broadwayworld.com/board/readmessage.cfm?thread=963561#3533883
http://www.broadwayworld.com/board/readmessage.cfm?thread=955158#3440952
http://www.broadwayworld.com/board/readmessage.cfm?thread=954269#3427915
http://www.broadwayworld.com/board/readmessage.cfm?thread=955012#3441622
http://www.broadwayworld.com/board/readmessage.cfm?thread=954344#3428699