Let the mark-ups wear off. I'll wait until MSPR (or less).
I'm just a common consumer that digs the concept car; for me, the Challenger is the 2 door and the Charger is the 4 door. The Challenger should only be about $2K more than the Charger MSPR. I compare those cars to each other. Then I would compare the Challenger to the comparably equiped Mustangs... although I wouldn't buy a Mustang.