Help to identify passenger side hard plastic line under fender liner

[pshovest]

Originally Posted by wpoll

.......it appears that the compressor is under the car, directly below the front right seat. This hose wold easily reach there.

That would explain the location of the intake filter, need to avoid injesting water. My E39 Sport Touring had the compressor assembly in the center of the spare, under the cargo floor. Again it seems odd they didn't put it closer to the rear axle.