1st,tell us upto what extent u want to modify ur car?how much money u want to spend...then we wud tell u.
few common things shud b...
chnage the rimz nd tyres.put any high end tyre wid 15 inch rim.tyre size shud b atleast 2-5/15/50 (low profile)
then get ur hands on sum side skirts,powered side view mirrors power windows things etc...lowere ur car about 2inches.get window tints.put an exhaust system,air intake system.4-tip plugsput fog lamps,extended front and rear bumper.if ur car is black,get black and red lather seat covers.note that the stiching shud b black on red lather nd red on black lather.