I found a 8" fosgate p2 sale for pretty cheap and I was wondering if that would be enough bass for my car? Or should I just get a 10"?

 

Enough bass is subjective. Some will be perfectly fine with 1 8" or 1 10" subwoofer. Then there's others who won't be satisified unless there are multiple 12's or 15's.

So it's all about what YOU like. With 1 10" i'm perfectly happy, and I've heard a single 8" and he's pretty happy too.

 

Hrmm maybe this would be a better question. How would this 1 8" fosgate p2 compare to a 10" jl w3 v1 since thas what i used to have?

 

Compare the specifications of the two. A bigger cone generally provides lower bass.

A single 8" or 10" woofer is sufficient in most cars at providing bass to "accentuate" the music and fill in the gaps. If you want the big boomy stuff, you need bigger woofers.