//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif Here's a thought: he is 16 years old and his parents are buying him a vehicle. He seems pretty grateful overall and seems to be moving on with the fact that it's not the vehicle he "wants". There's really nothing he has to prove here. Get a car bought for you, move on, and install a system.
This isn't a parenting forum.
Now with this said, I would do 3 10's sealed. Depending on your budget, you really have a lot of options. Another thing you could probably fit is 4 8's ported. That would really thump. I've also seen many trucks with 2 12's sealed in them.
Just let us know which you would prefer, and we can give you more suggestions.