I removed the plastic scuttle panel in the engine bay today but I was unable to find the ECU on the driver side. Does anyone know where it is located? And do they still use those anti-tampering security screws in this model?

In the plastic box that the main wiring harness comes from !
Yes vag still use the security bolts

always security bolds on audi
follow the big bunch of cable to a black box
the ecu is inside.

not true

My A5 sportback has nor any security bolts.
I dont even imagine, how could put this metal cover on plugs in there. There is no place so much for this.

Yes there's actually enough room for those
Seems that new models with tuning-protection softwares, there's no security bolts anymore.
Anybody else noticed this?