So what sound system's have you got in your cars? Ive got... Kenwood mask head unit. Alpine MRVF540 V12 4ch. Running a pair of Vibe 6*9's in parcel shelf. (and some components up front soon!) Alpine MRDM500-Digital mono block. Running a Magnat XTC 15'' sub in boot! I think it sounds ok, deffinatly need some components up front tho as its all in the back, then i can turn the 6*9's down a bit as there flat out trying to keep up with the sub Which rocks.