Sounds like a Russell Peters skit. “Then just for grins, let’s set the natural frequency at the speed most of these cars will be driven.” I swear, CalTrans steamrollers (they don’t still run on steam, do they?) have a flat spot so the road causes vibrations at 60mph.

Is there a tire plug that’s stiffer than the tire’s tread?

Sixto
98 E320s sedan and wagon