Best subwoofer for a 2000 Mustang Convertible?

Hey everyone,

So for context, before this Mustang I am about to buy, I had a 2001 Jeep Grand Cherokee. In that Jeep I had a brand new Rockford Fosgate P3 12" sub. I still have said sub, and it isn't even fully tuned yet due to not being fully broken in. I am considering doing an entire speaker replacement for the car, all from RF, and obviously putting the sub in the trunk. However, is the sound from the sub going to be as good as when I had it in my Jeep, due to it being closed in the trunk as opposed to being in a full open space? I saw someone near me selling a Genius Audio Vulcan v11 12" sub, that was super expensive by the way, and I considered getting that sub instead. However, I can't find any reviews or reddit posts about this brand, so I am very cautious.

Is the P3 and speaker replacement going to be a good match for my Mustang, or should I look for something more powerful?