I had a 94 with a 12 orion and a small amp. It pounded! You wont need 2 if you have the right box, sub and amp. My box was like 12x12x15
yes a ported box will rattle everything if its ported to nowhere....aka facing the trunk lid loljust giving some advice the reason i like the single 10 inch sub is that is about all your trunk can really use 2 12 inch subs in a ported box takes up a lot of room and the bass wont be very clear or deep and you will rattle you car to pieces one ten in a ported box will hit very deep and still hit the punchy rock stuff with authority and you wont get all the rattles just not enough volume in the trunk