Air Intake for BMW 5 Series 525i 528i (1997-2003) 2.5L 2.8L 3.0L EnginesThe E39 chassis is widely regarded as the last "true" mechanical 5 Series, but the factory intake system was designed for silence, not performance. If you feel like your inline six is choking at the top of the rev range, it's because the stock airbox is starving it. Its time to delete the restriction and let that Bavarian motor sing. Performance High Flow Air Intake System for BMW 5 Series (E39 M52 M54) For the BMW enthusiast, the E39 represents the