there is no "best" subwoofer out there...it all depends on which subwoofer....which amp powers it....if you bridge everything correctly....if it sounds good in your car or not...I think subwoofers sound better in hatchbacks...juss my opinion....I dont know about anyone else but i think a pretty freakin' good subwoofer that is out there are Kicker Solobaric S12L7...juss my 2 cents...
Kicker solobarics...