Where it the wagon, I'd immediately say the CTS-V. But coupes are a bit harder for me to decide (well, between the M3 and CTS-V at least. Just not a Mustang person. Shame on me I know). I find the CTS-V coupe almost excessively, um, 'fat' when looking at it. The M3 (to me obviously) has better lines. I've not…