Open SparkIV and press browse.
Scroll down to the bottom. There you will see models- Cdimages and textures.
Open textures by doubleclicking it. Then Scroll down (or use filter) till you see "policecomputer.wtd" click on this and press Edit.
First click on badge_dds3. Then press import.
import the file with the same name.
Do the same thing on the files with the same name as the one in this download.Remember! you must click one time one the files in SparkIV so you mark them before you import anything.
P.S: if it doesnt come up in game simply do the same thing all over again. SparkIV might glitch out sometimes. dont worry.
EDIT: Put the PoliceBG.PNG here: GTAIV maindirectory/scripts/LCPDFR
and remember before you start the game Make sure your folder options show all extensions (even known ones),
you can change this setting in your Control Panel. Then, rename the file to "PoliceBG", remove either ".png" or ".jpg" and you're done!
It will come up a warning saying that the file might get useless or something. click yes or ok or you know..proceed with the operation ;-)
Then the file will change appearance. Dont worry....this means SUCCESS!!!
Credits to Corleone for making the cars.
Check out his youtube channel: Norpolice123