You can try noyz boyz, they did some custom work on my m5, they aren't cheap but they did a good job and the sound is incredible. They are in scarborough
www.enthusiastauto.caNeed a car???
--'00 BMW ///M5 .:Jet BLK/BLK:.Individual- Modded
--'07 BMW M5/6.:Indianapolis Red
'91 BMW 850i J Spec Modded
'88 BMW 635CSi Lowered
'81 MB 500 SEC Koenig WILD RIDE