The MSAR used to have deadlines, I presume they still do, however, I paid no attention to the BA/MD programs, so can't say if those deadlines were included. Something to think about is that even if you are able to turn an application in, if they have been reviewing apps for two months or so, they may have already decided who they are going to offer spots to, so you would have to be better than the people they have already invested energy in when they decided they were going to accept them. However, if you are spectacular, go ahead and apply. As to all the posters who say to take the traditional route, remember that only you can guess what will make you happiest.
I'm finishing my first quarter of medical school, and I've never been happier or enjoyed school more. I liked undergrad a lot, and even liked high school, but this is spectactuarly interesting, and I think that given the opportunity to re-do my undergrad applications, I should have applied to accelerated programs. Of course, if I had, I might not have the wonderful partner and friends I have now because I would have been located elsewhere, but I still wish I could have started med school sooner (and that they could have just been wherever that hypothetical accelerated program was...)