I have to replace my fin antenna on my 2015 Cadenza (with panoramic moonroof). I dropped the rear dome light, but there is not enough room to maneuver to get to the nut holding it on. I thought if the headliner could be dropped a bit, i might bet to the nut. any instructions how to lower the back part of the headliner? Im also worried about the airbags too.... couldn't find any cadenza specific instructional videos on youtube/google.. suggestions?