You can hear the explosion in the video, just need to apply a bit of a high cut filter. The sound of the gearbox and (what I would guess to be) wheel slippage on the shoulder of the road while reversing the vehicle masks it.
The offset between visual/audio of the event is about 750 ms, assuming a speed of sound of 344 m/s that would put the camera around 250 meters from point of impact.
Looking at loudness, not knowing many of the specific parameters, assuming 170 dB at 1 meter distance (now this is a bit of a thumb suck), that would decrease to around 110 dB at a distance of 250 meters, 8 mm of bullet proof glass would probably give an additional 30 dB or so of attenuation.
All under correction of course