In my car taking the headliner off involves removing 6 bolts (one in each pillar) and then popping out some retaining clips. I was surprised at how easy it was when I ran the wire to the rear camera. Headliners were notoriously difficult to deal with in the old days. There was even space to tuck the excess wire away to keep it neat and tidy looking. My camera just sticks to the glass using a sticker so attaching it was no problem either.