Not too sure about 'Structural Resonance'. The speed is increasing, so any driving vibrations are increasing in frequency. A 'resonance' would only appear at one frequency.(= one speed.)
Back in the pre MOT days, when 1/4 a turn of steering wheel play was the norm, out of balance wheels would vibrate at 45 mph. Two mph faster or slower would be Ok, the resonant speed was 45, which was about the speed of the traffic those days..
Last edited by scifi; 17th Apr 2019 at 09:16.