Recently replaced what I think was the OEM headliner with a knockoff from Rockauto. The OEM had a heavy velcro-style strip to either side of the rear-view mirror (each about 8 in x 1.5 in). One side of the velcro stuff was still firmly anchored to the roof shell in my '94 ECSB C1500. The mating stuff on the headliner had de-laminated from the headliner shell (possibly / likely from water intrusion due to a leaky windshield seal
).
The Rockauto replacement came with a strip of velcro about 30 in x 2 in, and instructions to cut the strip into sections for either side of the mirror, and place these close to the edge of the windshield. Meant to grab a few pics, but alas, was too focused on getting the task done to grab any photos.
So far so good - the velcro is holding very well, though its only been a few weeks and we've not yet had temps over 90dF.