Well, the humdrum pace at the start of this advertisement builds it up actually very nicely. The course is expected until…
…until the gun is pulled on the car and not on the girl. That is the truly astounding moment in the advertisement.
According to the dictionary, astounding carries the following meanings (mentioned with usage):
1. capable of overwhelming with amazement; stunningly surprising.: the events of the evening were truly astounding. No one could have anticipated that a murder would take place in the house before the evening ended.
There is also an astounding piece of machinery in the advert: the Audi R8. That is something to be marvelled at as well.