12W7 will tare down your crossfire! I have 12W1 V2 hooked up to Alpine PDX-4.100 (two channels bridged for sub) and Alpine SPR 17-S speakers, and my car is almost going to fell apart...I would avoid W7...I tried 2x10W3 and that was....well lets say interesting My friend had in mazda 3 alpine 15" Type R sub...His stop light fell apart, and back window wiper stoped working....