Thank you for all the inputs guys. Man, I love this forum... if y'all are not helping me out with tips and tricks for buffing, it's helping me out with my car dilemma.
For those of you who posted that I test drive a 5.0 and an M3, I already have. The 5.0 definitely put a smile on my face. Wife and I test drove the coupe and vert back to back. That power is intoxicating. I remember my wife's comment on the 5.0..."Wow, I am surprised. This thing rides really nice." After that, I punched and she clenched on for dear life.

My only worry about the 5.0 is that it's a "muscle" car... my wife comments on that everytime. "It doesn't look as nice as your G"..or..."Do you really want a muscle car?" So I find myself thinking twice all the time. Besides that, the 5.0 may have a tendency to be "common"...having other people have the same car as me.
As far as the BMW is concerned. It rode really nice too (of course, it's a bimmer). But it doesn't have as much power as the 5.0. But it's more refined. It doesn't look as good as the G, in my opinion... it's more "common" too, but not to the extent of the 5.0. Then, it's used

with possibly more miles than my G... then also the maintenance costs

But it rides like a dream.
The M3 would be like a scalpel. The 5.0 a blunt hammer (a BIG hammer). The G would be like a very sharp kitchen knife (in between the 2 I think).
As far as affording it... no worries. With the trade in value of the G, I plan on paying the whole thing in one swoop... no loan.
sigh... decisions decisions... I should have tallied how many votes you guys have all said. So far, I think the 5.0 is winning by a hair, followed by keeping the G