I hate to sound negative, but I don't think a higher MCAT will necessarily make up for low grades. Although it may vary from school to school, you're better off taking more classes over the next couple of years to raise your GPA. This would be particularly true if your science GPA is lower than 3.0. In many adcomms minds you won't be curing the problem by taking the MCAT again. Instead, they'll want you to take steps to raise the GPA. Like the above posters said your MCAT score is solid. I would not take it again unless you are sure you can do much better.
To follow up on my above comment. I know someone who got 8v 10p 12b R the first time they took the MCAT, and then got 6v 10p 12b Q the second time. Retaking it did not help them, and this is not unusual. Most people who score in the 30s the first time they take it do not improve significantly and often score lower. This is not to say that you won't score a 38S the next time you take it. But be very careful. The MCAT is not the problem so don't waste energy trying to improve that at the expense of improving your grades. Either way, good luck!
I will say there's more than a grain of truth to this. I retook (original: v8 p9 b8 and something awful for essays) and upped my scores to 11 8 10 R, but i think in a case when you already are scoring well they know you can tackle the MCAT and that isn't the issue. I agree re bolstering your GPA (and, since you're smart and probably just weren't diligent re classes, it'll be easier than retaking the MCAT a million times). Btw, is 3.0 your science gpa or overall? This matters as well.