I added a few more links, I have an actual tune so I can't comment on the JBD but if you are under warranty I would go that route it would be easy to just pull it out before visiting the dealership. I read about it after i had my tune and it seemed like a great option but I got my tune the same day as I got the truck so it was too late.

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X5M Eisenmann exhaust, de-Catted down pipes, 22" HRE wheels, ECUProgram stage II (700hp) tune
X5 35d Tuned and Lowered