Is this normal? I experience low frequency noise (deep vibration/resonance) on tarmac with small vibrations. And on rougher roads. The liftgate sits pretty tight now, I've adjusted the screws as far out as I can. This is driving me nuts and I am starting to miss my previous car.. Please see attached screen shot from Dynabel Soundmeter app that I ran during driving. If anyone else could run a similar test in their car, I'd be grateful. Comments or tips appreciated!