amp power cable

[spmir1]

hi guys i am wondering how you get the amp power cable from the engine bay into the cabin.
I have a right hand drive. The battery is on the passenger side.
There is a grommet in the engine bay in the centre slightly to the passenger side, and a grommet in the passenger side wheel arch. I can't seem to find where the grommets lead to.
Any help would be much appreciated.
Thank you.

[2way]

There's also one on where the hood release cable enters and there's an extra nipple that you can cut the tip off of.