er 2in1 system ICE + BOV sound in 3 simple steps
step 1 :1st get a an HU-headunit which can play mp3 , or a HU that can play cd also enough la
step 2 : go online search for ur fave bov sound - wheter ssqv , blitz or even the duck 1 - ( refer youtube - search duck bov ) , save the sound and burn it to a cd
step 3 : when u change gear that time blast kaw kaw ur ice system then hit play
step 4 : profit