You're getting a bit confused, I'm afraid...
You still need a glide year, even if you do everything in a year. You need to apply and be interviewed.
Typically (chronologically):
Summer + Autumn + Spring of post-bac
Early summer MCAT
Apply during summer
Autumn/Winter Interviews
August (of year 2) - Start Medical School
You really can't take the MCAT without covering the material in some form. It's not going to work very well... You need to do the post-bac courses first.
Similarly, you can't really apply while you are completing the bulk of the pre-requisites; the schools don't know what your grades are, and they have no MCAT. In addition, you can't get any letters of recommendation from your post-bac tutors, since they haven't met you yet
The thing which might be confusing you, is that some post-bac programmes offer 'linkage'. This is an accelerated track for post-bac students that bypasses the glide year. Pass your pre-reqs with enough skill, and a good MCAT and you get to join the class entering medical school that August. But the post-bac programme only offers the link with certain schools. For example, Tufts' 2 year post-bac has a link with Tufts' medical programme and a couple of DO schools. Bryn Mawr links with Brown, Dartmouth, Drexel, George Washington, Jefferson and a few more. It's a limited list which varies depending on the post-bac programme. Some don't have any linkage, so you just apply through AMCAS and have the glide year as normal. At a school with linkage, you can still do AMCAS and the glide as well, to apply to schools outside their linkage.
If you want Harvard, BU, Cornell, Columbia, Penn, Duke, UC* or any other of the big name schools, however, you are unlikely to find them linked to any post-bac except one that they themselves run, and that is rare (e.g. Tufts post bac is the only one that links to Tufts, while Harvard post-bac doesn't have linkage at all).
The USNEWS & World Report Guide to Medical Schools has a proper list in the back of it; it might be a good idea to read that section of the book and decide what your options are.
I hope that helps a little...
