No offence to the post above, but Power Acoustik, Alphasonik, Auidobahn and the likes are all the botom of the barrel. They are lines built by the cheapest bidder in the far east. (thus the quality control issues that was eluded to). Research the amplifiers even more to find out exactly how overrated most amplifiers truly are. Hopefully the CEA2006 ratings will put and end to this. As of right now, too many brands prey on the uneducated consumer, this leaves some of the people like me to show a differerign side of the industry.
The only thing I am trying to sell you, is me. Take my recommendations for what you think they are worth. If I recommend a product, maybe you will research it and come back with questions or maybe you will come back and tell me that I was bang on. Most people take me at my word (you'll know when I am kidding you).
Now as far as the car goes, 2 15's in the trunk of a 95 Stang is going to be difficult. This is due to the fact that 15's for the most part take up space and a lot of it. I pointed out earlier that it is all about the box. Whatever subs you choose, you must have the exact size enclosure available to go into this car. This car does not lend itself to a nice and easy drop in sub box system IIRC. If I am correct, the box has to be built either in the vehicle and so much for getting it out or needs to be built in pieces to get it into the vehicle as the trunk opening is too small.
Bigger does not necessarily mean better. 2 12" subs in the proper box will tear a new butthole for a pair of 15's in the wrong size box. Look at the space you have available first, then figure out how the box is going to go into the vehicle and assemble (and mount securely as a loose box wastes output), then choose a sub based around these factors.
Big power = big power system, if you are running a stock electrical system with no imminent plans on upgrading it, big power is not going to do to much for you. You cannot magically make big power from an amp unless you deliver big power to the amp. Consider some basic math here. A difference of 3 db on average (not all cases) results in something that you can tell is louder. A difference of 3 db in the audio world as a doubling of something. A doubling of woofers from 1 to 2, 2 to 4. A doubling of power from 100 watts to 200 watts. A doubling of power from 1500watts to 3000 watts. However the most benefit you will gain in your system as far as output levels go, is going to come from the box. It is all about the box and how it couples with the vehicle (called cabin gain). If you want loud and who cares about how it sounds, find the resonant frequency of the vehicle (no e-tailer can do this for you - go to a shop and have a sinewave sweep done and then zero in on the frequency), next build and tune your box to this frequency. This is the road to loud one note bass response but it sucks for listening to everyday music.
If you want to listen to your music, the word compromise must become part of your vocabulary. A ported box as a general rule will also give you a minimum of 3 db more output (in most cases much more in the lower octaves where your deep bass lies and the ability to piss of the entire neighbourhood). Go through what I have written and do a search on some of these topics here on the forum and ask more questions. I am hella busy here at the shop right now and will respond when I have time. Hope you take my advice for what it is and understand a little bit more as to why I am anti e-tailer. No e-tailer I know of right now would have spent this time with you when they could be selling to another unsuspecting customer.
Top Secret, I can tell you but then my wife will kill me.