Why BMW Panoramic Sunroofs Leak (and What It Costs to Fix)
Image: BMW 5 Series (F10) Complete Sunroof SERIES COMPLETE SUNROOF for £141.85 at MT Auto Parts Water inside the cabin of a BMW is one of those problems that gets worse the longer you ignore it. A damp patch on the headliner becomes a wet footwell. A wet footwell becomes a corroded module. A corroded module becomes an expensive repair that traces back to a blocked drainage tube that could have been cleared for almost nothing. BMW panoramic sunroofs are one of the more common sources of water ingress on UK cars. Not because they are badly made, but because they rely on a drainage system that most owners do not know exists, and therefore never maintain. How the Drainage System Works — and Why It Matters The BMW panoramic sunroof is not a sealed unit. It is designed to let a small amount of water past the glass seals during heavy rain, then channel that water away through four drain tubes, one at each corner of the sunroof frame, that run down through the A and C...