Dinan Free Flow Axle-Back Exhaust Black TipsQuad exhaust tips have been a signature feature of the most powerful letter in the automotive sphere for quite some time. It is a hallmark of the brand that Dinan has long embraced, limiting its own quad tip usage to those M cars that already sported like tip quantity from the factory. That is until now with the release of the Dinan axle back exhaust system for the G20 M340i and G2x M440i. While some may scoff at the feature being implemented into a