Some additional pics as to how much the exhaust tips stick out. Fwiw, it's the same as the Akra exhaust, I think.
My mechanic informed me that after you knock out the oem sleeves, there is a raised section near the end of the exhaust tailpipes, and his instal of these CF tips was exactly in line with the raised section of the original tailpipe - easier clamping point, and also a standardised point to start from to ensure that all the CF tips were secured at the right place.