Many of those questions came at a city council committee Friday.
Emanuel's attempt to make his predecessor, Richard M. Daley's, parking meter deal "less bad" for the city has come under new fire from aldermen, and they don't care how fragile the pending revised contract might be.
"This is a delicate compromise -- the old humpty-dumpty kind of thing," said corporation counsel Steve Patton.
The city's top lawyer warned that if aldermen reject the deal as negotiated, the private company, Chicago Parking Meters, LLC, might take its offer off the table.
"That's what's most troubling. We've been told this is a take it or leave it deal," said 42nd Ward Ald. Brendan Reilly.
The company holding an ironclad, controversial lease on the parking system for another 71 years has offered to turn off its neighborhood meters on Sundays if it's allowed to extend its hours in the busy Loop and Near North Side seven days a week.
"We've been asking since the day this deal was introduced for an explanation of the figures," said 43rd Ward Alderman Michele Smith.
Smith and other aldermen fear the parking company will make much more money from longer hours downtown than it will lose on free Sundays elsewhere.
In a letter from their law firm, Chicago Parking Meters executives refused a council request to testify at the hearing.
"They're hiding under an attorney client privilege," said 2nd Ward Alderman Robert Fioretti. "We should know why this is a good deal for them or a good deal for the taxpayers."
Mayor Rahm Emanuel and most aldermen could benefit politically from free Sunday parking. The extended meters downtown are concentrated in Reilly's 42nd Ward.
"I'm inclined to vote no. I think this is not a good deal," said Reilly.
The 5th Ward's Leslie Hairston wants legal action against the law firms that advised the city when the deal was signed, including Katten-Muchin, the firm that currently employs former mayor Richard M. Daley.
"Have they talked about suing the lawyers that crafted this deal for a year-and-a-half? And who knew what and when did they know it?" said Hairston.
Hearings on revisions to the parking meter contract continue next week. The finance committee will try again to get company officials to testify.
The inability to get accurate projections on potential revenues and losses remind alderman of what happened the first time around before they approved what all agree was a horrible deal for the city.