Ran another W204 C63 the other night, not a 507 but I’m assuming he was tuned so should be a similar outcome. He got me, but I held my own pretty well all things considered - golf clubs in the back and all.
APR DP with APR tune. It’s been fun but I’m switching back to my stock DP in a few weeks to avoid any future complications. Car is definitely quicker with a DP though, and I’ll miss the deeper tone and DSG farts… not worth the risk though