Dinan Free Flow Axle-Back Exhaust - 2018-2020 BMW M550iThe G30 M550i exhaust ushers in a new era of Dinan exhaust design. To date, Dinan has been synonymous with welded on, thin walled tips and a philosophy of exuding a civilized note when you want it to be, and a pleasantly aggressive one under hard acceleration. While the mantra is maintained, albeit tweaked with the emergence of mid pipes and resonator eliminators to those who want an even more aggressive sound, the styling of the tips is being