I also considered the GTR, but the looks and quality are just not for me. Both are awesome cars and have very similar performance numbers.(GTR being a killer from launch, M5 being a killer from higher speeds) Two completely different monsters. What he said, you should also consider the e92 m3, I must say these cars just have to much power for every day driving. Or you could get an m5 for your DD and a 911.
Try fitting 4 Girls in your GTR