yeah actually that is what most people do.
Senior year of college, they begin to apply for SMP's at around January, and a few months later, they take MCAT (if not taken previously) and then apply to medical school. On the AMCAS they indicate that they are going to be starting an SMP and during the SMP, your SMP advisors at your new grad school update the medschools to which you applied about your test grades.
check out the post-bacc forums, there's a plethora of information.
admin can you please move this to "post-bacc" forums?