@604x4BC while the head liner is out is the perfect time to find leaks, they are really easy to see and fix.

 

I drove mine around for 6 months without the headliner in it until I finally found my leak (rear sunroof to body seal). Painted the headliner, looks beautiful. Fast forward a few years, and now I have another new leak at my passenger A-pillar......I'll eventually look into it.