I did my fitcamx front/rear install recently and I also used that grommet. Takes a bit of patience to get it through. I'd recommend applying some silicone grease. I also installed a third light blinker while I was at it.
Did you get this one?
https://acuityinstruments.com/products/acuity-pedal-spacer-for-the-lhd-10th-gen-civic
I find it very hard to heel toe as well. My ND Miata on the otherhand is a joy to heel toe.
Just stuff in the cables with the rest of the harness lol.
And to answer your question, I'll post here for all to see:
I got this https://fitcamx.com/collections/honda-civic/products/fitcamx-dash-cam-for-2023-2024-acura-integra
Just follow their instructions on YouTube. Don't be afraid to yank...
Just installed the Accord mirror with the harness. Overall wasn't bad, but I've done this for multiple cars so I'm familiar. I would rate it 4.5/10 for difficulty. Was a bit harder for me since I have the FitcamX installed and the cables got in the way. Definitely worth. One small difference is...
So it's not just plug and play right? Since you mentioned removing the A-pillar, I assume you followed the Accord instructions? I was hoping since the mirror is already powered for auto-dimming that it would be plug and play.. :(