1.33 engine strange tapping on idle

[dobrik]

Hi,
Since the car (yaris 2012, european, 1.33 CVT) was taken from dealer there was strange irregular tapping sound on idle when engine is fully warmed up (~20 min drive). I've pointed out to dealer on first service and have got the answer that it was regular vvti sound, the same said regional Toyota representative. Oil was tried from 0-20 to 10-30 tapping was always there. Here is the recording I've made today in the parking lot after 1 hour drive https://www.youtube.com/watch?v=lpXm6DqkKwk
The tapping is irregular, high sound, when you hear it once you can't unhear it :). At the dealer's they say that I shouldn't worry as engine is under warranty, but still I want too get to the bottom of this, any opinions?
BTW, I've heard the other cars from the same period - some got the same tapping and some not.