Mass Air Flow Sensor / Meter / MAF Fits: 2003-2006 BMW 325Ci, 325i, X3, Z4 In order to avoid return hassle and save yours and our time, you must cross-check indicated reference part numbers against those found on your old unit. Do not rely on vehicles compatibility list, which is presented for the reference purpose and shouldn't be your guide to determine compatibility. If you are unsure, you may call local dealership (auto parts dept.) to obtain correct part numbers or ask your mechanic. If you would like us to help you, please contact us and provide your vehicle's detailed info such as: Make/Model/Year/Engine/Full VIN# and we will do our best to find compatibility. PART REFERENCE NUMBERS: OEM: SIEMENS/VDO: 13627513957 13627566984 5WK96471 AIRTEX/WELLS: CARDONE: 5S2991 SU6951 7410124 74-10124 *Please cross-check indicated OEM reference codes against those found on your current unit. You may call local dealership (auto parts dept.) to obtain correct numbers. COMPATIBLE VEHICLES: * Models presented for reference purpose only! Year: Make: Model: BMW 325CI (2003 - 2006) BMW 325I (2003 - 2004) BMW X3 2004 BMW Z4 (2003 - 2004)