porkbone:

 

Assuming the speaker IS wired @ 2ohms, if I asked the car audio place to swap the sub into a ported box (swap raw power for spl) and wire the speaker into 4ohms instead, would that work? Or maybe add a 1 - 2 farad cap as well? What do you think the difference in overall sound would be, similar or much different?

 

If it were me I'd do one thing at a time. Try the change from 2 ohm to 4 ohm first, (assuming that's an option). Then if you want more base try the ported box. This way you know what has worked and you may discover you don't need to go to the expense of changing the speaker box.

I doubt the capacitor would provide any benefit in your situation as the woofer should be adequately powered by the amp.

Before you go telling/suggesting to them what they should do, let them have a look and see what they come up with. They are (or should be) the experts, there's nothing worse than an layman telling them what to do. They may come up with some options for you to choose from. If they don't have any ideas ask how the speakers are wired (2 or 4 ohm) and if 2 ohm, ask if changing to 4 ohm is an option. If they are already 4 ohm ask about the ported box option.