If you have 3rd row seats it is definitely self leveling, typically self leveling suspension makes hissing sounds when you unlock the car or when you close the door after getting out or lock the car.

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2008 E70 X5 3.0si
Sport | Prem | Adaptive Drive | Tech. | Cold Wthr | Rear Climate | 3rd Row | Running Boards | iPod/USB

2019 G30 530e
Sport | Adaptive | Drv. Assist+ | HK | HOV Access

2018 F83 M4
Comp. | Exec | DCT | First M Car

2009 E93 335i (Sold)
Sport | Prem | 19" 230 | Logic 7 | iPod/USB | Sat | HD Radio | Comfort Access | Heated Seats | Pure Joy

E36 328is GoKart (Sold)
Manual | HK | Trip Comp. | 17" Rims