Get a G37 IPL.
As others said, don't get another M3. Mix it up! I personally don't like the ISF. But I've also never driven it before. I was going to suggest checking out an RS4, but I see that you want an automatic.
Which leads me to my vote: C63! The fact that it doesn't come in stick is the biggest reason I wouldn't get one (aside from the looks). So if somebody made me get an auto, I'd see it as God himself telling me to get the AMG.
Also, I would look into a 335d. In red. My friend has one, and I like it. Great gas mileage (he sometimes gets 40) and torque available almost immediately in the rev range. Although it does only rev to around 5,500 and it sounds pretty uneventful on the way there.
PS: Or you could get a clean E36 M3 sedan in auto and spend the rest on modding the bejesus out of your cars!