I want to add a subwoofer to my IS250 2014 stock audio system but I'm not too knowledgeable on what to get, how to install, etc. I want to add one JL 10w3v3 but not sure if I should get the 2 ohm or 4ohm sub? Which JL amplifier should I get with it?

 

It's basically what amp u run. If u run the jl hd or the slash amps then It doesn't matter what ohm u get. If u get the jx or xd then u need to get a 2ohm sub.