Install like any other vehicle mod.
Load the vehicles.img file with either SparkIV, or OpenIV replace the Sultanrs.wtf and the sultanrs.wtd



Vehicles.ide
--------------------
sultanrs, 	sultanrs,	car,		SULTANRS,	SULTANRS,	VEH@LOW,	VEH@LOW_LE2_RI2,	100,	999,		0.2391,	0.2391,		0,	5,	1.0	,1,	ext_all+ext_strong+big

Props go out to Kotton for the help with my first mod.
Link to Kotton's website http://s1.zetaboards.com/Kottons_Chop_Shop/site/

Wheels modeled by me (Twiztid Axe - aka ApeX Skins)
Trunk spoiler from the infernus, and the wing above the rear window is from the 
stratum and the piece on the hood is from another stock GTA vehicle. 
but I can't remember which one :P