Road-induced vibrations are in the scope of various environmental testing protocols, e.g., for packaging vibration testing (PVT) purposes. This field matures with well-understood methods for analyzing amplitude-type non-stationarity (NS) in road vehicle vibrations (RVV). Albeit frequency-type NS is well known, only suggestions are provided for processing the phenomenon in PVT. Both types of NS can be jointly investigated in the time-frequency domain; thus, the current study initiates the investigation of spectral non-stationarities (SNS) in RVV. Three vibration series were recorded from 118 km traveled distance supplying an empirical insight.