BMW vibration peaks at 1500 RPM after jack drop

I’ve developed a vibration after I accidentally dropped/lowered it abruptly off a jack. It has a slight vibration at idle, but it peaks really hard at exactly around 1500 RPM, then tapers off above that RPM. It feels more like it’s coming from under the seat/floor area rather than through the steering wheel, and there’s almost no steering wheel vibration. It still happens in neutral, doesn’t seem very speed-dependent, and the AC slightly changes the vibration. I found a broken plastic piece sitting on top of the undertray and some damage to the tray itself. Removing the tray seemed to reduce the vibration, but it’s still slightly there. Does this sound more like exhaust/heat shield resonance or underbody contact rather than engine mounts?