Not usually. Because most Saturns run a 4-bolt lug pattern, while all Crown Victorias run a 5x.5.5 5-bolt lug pattern. On top of that, Saturn cars run a 14" rim profile, whereas the Crown Vic has been setup to run a 15" rim.
Not without serious modification
Yes
Yes
Yes
Yes
Mustang wheels will fit on a 2000 Crown Vic depending on the year of the Mustang.
Can 24's fit 99 crown Vic without lift kit
Yes
can 5.0 engine fit in 1999 crown victoria
Yes
will chrysal rims fit ford crwn vic
Yes