I would say that if your GPA is above the class average of 3.3/3.15ish science, then you probably have a shot. Apply very early, like January to maximize your chances. I think it would help a lot though if you could retake the MCAT next April and score 27+, 30+ if possible.
However, if your GPA is at the national average for accepted med students, like 3.6/3.5sci, then what you really need is an MCAT prep course, not the SMP. It is really more for people with low GPAs and average to good MCATs. I know that they do make exceptions for people with like a 2.8 and a 37, but I don't know about the other way around, because really it is a program to compensate for a low GPA.
Hope that helped.