Ok first I should tell you that cars have a much larger gain at lower frequencies than house rooms do. If you want to use it in your house, then you will have to build a different box for the sub. If you don't know what type you would build, then tell me what you want to use it for (music, music type, movies, games and a percentage of each) and then tell me how big the room is you plan to put it in. Oh, and I will NEED your sub's model.
What do you mean by a domestic amp? If you want to use that amp in your house, you'll need either a high-capacity 12v battery, or you will need a power supply. The amount of current required will make that PS expensive. In fact, it would be better to just buy a pro amp to power it. From Behriner, you can get a $300 amp that will put out up to 2.2kW depending on the resistance.
So tell me if I misread your post and I'll get back to your OR someone else here will say something.
Most car subs don't work well in a home environment. They do not have the proper alignment and damping to provide tight, extended bass response and instead put out one note boomy bass when removed from the car environment. The problem is the difference in gain provided by the two spaces as Andre mentioned. Car subs are meant for cars and home subs are meant for much larger spaces.
If you insist on trying this rather than buying a proper sub for your home system, I'll assume this is a passive subwoofer. If so, you can run this sub off your speaker outputs on your Onkyo but you probably won't be level matched to your main speakers. If the sub is playing louder than the mains, buy an L-pad at Radio Shack and trim the sub down in level.
Beyond that you're going to have to supply more information.
Another thing is that if the woofer is in a sealed box, you can buy something like a configurable Linkwitz-Transform.
The good thing about them is that you can dial them in to a specific setting and they will equalize your subwoofer and as a system, it can be made to act like a subwoofer made for being in a large room.
The bad thing about them is that they can cost $250-$400.
If you know the exact specs of your sub, you can build one for about $20 with average-quality parts.. if you can build it, that is.
The point is, the money/effort required to 'force' what you currently have to be good would be enough to buy a pretty nice subwoofer.
If you built all the parts needed to make what you have work, it would cost around $100, but the difficulty of building/designing all the parts would take some learning. That's without buying the tools, too.
Andre, you're missing the point that many car subs just don't work well in a home environment. There's no reason to try forcing a sub to sound good in a home when its essential design isn't meant for that location. Now, if the only desire is to have boom, then you can stick whatever woofer you want in a home setting and you'll have boom without extension and without pitch accuracy. But, if that's the only desire, you can go buy a $99 "subwoofer" from a shop and obtain the same results - and it will include a cheap amplifier.