peeking between headliner and roof

[kenyee]

Anyone know how to peek between the headliner and roof easily w/o yanking the headliner?

Trying to track down an intermittent thunk noise in the roof. It's almost like there's a loose bolt that occasionally rolls into something and you hear a thunk to your upper left (left of the sunroof) as you're driving. Sometimes you hear it as you go up/down slopes. Sometimes you hear it when hitting bumps that wobble the truck from left to right.

Unfortunately, sometimes you don't hear it for weeks to months at a time, so it's hard to schedule an appointment at a dealer and hope to show them the problem. I hate it when you can't reproduce problems for them (like my glovebox area buzz that went away after I scheduled an appointment)-: