I have 4 Infinity Kappas that I used in my old truck and took them out before I sold it. They're the 2 way - 5x7 - model 572.5 cf. They sounded amazing.

Reasons why I'm considering using these in my S is because:

I'm cheap - why buy new speakers when I already have some.
I don't want to buy adapters or whatever to make new speakers fit. Plus I'm cheap and don't want to pay to buy the new adapters.
I have a hard top and no more vert top so I have plenty of space where the back deck is.

So my question is how much airspace does each individual speaker need? My cousin had Cervin vega 6x9's enclosed and they sounded incredible!! Or should I just mount them on a deck NOT enclosed? TIA!

Also I have an amp to power them so thats not a problem. And I have 10" Kicker solobaric I'm going to be using for a sub. Just have to install everything.