It depends, do you mean directly or outputting the signal from the reciever to an amp which will drive the sub? If its the former then you'll likely have some issues, if its the latter then it won't be any more difficult than a regular HT sub (well from the reciever anyways).
The problem here is that car subs are designed for a different application, and as such might not be that great for HT duty. You'll have to take enclosure and other things into consideration. It will depend on the sub and the enclosure you use how good it is. I think most car subs would probably be boomy and not offer a nice refined sound. This might be what you're wanting, and it'd be ok for music playback at a party or if you're a bass-head.
The last bit I'd like to add is to remember your neighbors. Ever had someone drive around with a sub cranked well beyond a balanced level in a car? Imagine that being stationary. Yes, people can do this with HT subs too, but most people don't own that great of HT subs (usually ones from HTiB setups which are pretty weak), and most people who want to put car subs in their house usually are wanting to crank the bass. So, please just remember there are other people (especially if you live in an apartment building).