for the past couple of months, I was feeling almost a bogging or hesitation in my 3.2. I would step on the gas and you could feel the car shutter and then get up to speed. I had my brakes replaced and the guy that did them informed me that both my axle boots were torn and open. I recently had the axles replaced at my indie shop and all the of the shutter/studder is gone. When my idie shop looked at the car, the first thing they asked was did I feel any hesitation almost like car needed a tune up. They mentioned that is one of the signs the axles are close to being on their way out. Not saying this is your issue, but something to look at.