You guys were right. In order to remove the rear panel, you have to remove the exhaust and heat shield (or at least seriously ease some bolts). Not complex but removing the rear panel without doing this is impossible... at least on a 2007+
I installed my new 2Bular 8X24. I kept the heat shield but cut it so we don't see it too much and used header wrap on the U section of the exhaust.
Very happy with the result although it is on the quiet side...
Cheers

Pierre