gtasa/data/handling.cfg
INFERNUS     1400.0    2725.3   1.5    0.0 0.0 -0.25 70  0.70 0.8  0.50 	5 240.0 30.0 10.0 4 P 	11.0  0.51 0 30.0  	1.2  0.19  0.0   0.25 -0.10 0.5  0.4		0.37 0.72 95000 	40002004	C04000		1  1	1

gtasa/data/vehicles.ide
411, 	infernus, 	infernus, 	car, 		INFERNUS, 	INFERNU, 	null,	executive, 	5, 	0,	0,		-1, 0.7, 0.7,		0

gtasa/data/carcols.dat
infernus, 2,3, 0,3, 1,3, 1,4, 45,1, 2,3

get that mod car colors make your game more cool ;)
http://www.gtainside.com/en/sanandreas/mods/86342-car-colors-mod/