also, i was hoping to get a square kicker....i want a 12" but i feel i wont be able to fit it in the trunk.

other option would be to get a round 10" and just use my current box but i can't see the kicker being any better than the JL unless i go with a 12" square design.

so i went to a car audio shop today and was told i should just buy another JL 10W3v3 instead of going kicker. so i think i shall do that!

Look for a single 2 ohm, or a dual 4 ohm.
Or buy another sub that's either dual 2 ohm, or single 4 ohm to pair with the sub you have already.

yeah that's what he said.
if i wire another single 4ohm in parallel with the other JL 10w3v3-4, it would create a 2ohm resistance. so i shall do that.