Should be 4 speakers. Two in the front dash, and 2 in the rear behind the seat.
Yes
( 20.0 U.S. gallons ) according to my Chilton's book for a 1989 Ford Crown Victoria
6x8
About two tons.
No
stock size is 5X7 in the rears
On a 1989 Ford Crown Victoria : ( there are 5 lugs per wheel , total of 20 )
According to my Chilton's Auto Repair Manual : A 1989 Ford Crown Victoria has a ( 20.0 U.S. gallon gas tank )
http://www.modifiedlife.com/1989-ford-crown-victoria-car-radio-wiring-schematic/ any car audio web page will have diagrams
My Chilton's Auto Repair Manual shows : For a 1989 Ford Crown Victoria 5.0 L ( 302 ) V8 : ( 39 PSI ) * the 8th " character of the VIN is an " F "
Ford Crown Victoria was created in 1955.
On a 1989 Ford Crown Victoria : The gas tank size is ( 20 U.S. gallons ) according to my Chilton's repair manual