Mazda 3 - how to connect to HS CAN bus

Hi, I would like to connect my CAN Bus Triple to both HS (High Speed) and MS (Medium Speed) buses on my Mazda 3 (2007).
I can hook to MS CAN bus through stereo or LCD harness, I know they both have the CAN pins for that bus.
Now I'm searching for a convenient location to connect to HS bus.
Obviously I could use the standard OBD2/J1962 external diagnostic connector, but I dont't want to expose wirings so I prefer to use an internal cable.

Can anyone suggest me how can I hook to HS bus?
Thank you

HS Bus should have some wires going to the instrument cluster

Looks like your connection to CANBus Triple was lost, please wait while we try to reconnect.