I am not sure if these are the best but I got 2 Sony Explod subs that I got on sale for $40 a piece. I got em at a wherehouse type stereo shop (the ones who don't put prices on any of their products). They hit very hard and now I got trunk rattles to deal with, lol...
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Black E0 SVT #2239 K & N Induction/Res Replaced w/str8 pipe
Silver accented interior
Sony Explod Audio stuff