Before continuing, backup your files if you want to restore to normal later.

Install the noose.wft and noose.wtd to vehicles.img using SparkIV or OpenIV in:
C:\Program Files\Rockstar Games\Grand Theft Auto IV\pc\models\cdimages
Overwrite all files.

Open up handling.dat in common\data with Notepad, find "NOOSE" line and replace with this:

NOOSE        1750.0 6.0 85 0.0 0.0 -0.37 0.0 5 0.19 1.0 150.0 0.22 0.65 0.7 35.0 1.30 1.10 14.0 0.13 0.47 1.7 1.1 1.1 0.10 -0.10 0.0 0.5 1.0 1.0 0.9 1.4 0.0 28000 440080 0 0 

Save and close.

Open up vehicles.ide in common\data with Notepad, find "noose" line, scroll to the right end
and add "+livery" to the line or replace this:

noose,		noose,		car,		NOOSE,		NOOSE,		VEH@STD,	VEH@STD_RI3,		100,	999,		0.2345, 0.2345,		0.3,	2,	1.0	,1,	ext_requi+ext_strong+livery

Save and close.

Open up carcols.dat in common\data with Notepad, find "noose" line and replace with this:

noose,		113,113,113,

Save and close (it's GTA IV default. If values are same like above, don't change)