What I found over the years is the cloth that is used drys out making it easy to tear or damage , along with the thread that was used to sew it all together, most others do to carrying stuff that's too long and end up punching a hole in it , or worse is nosy kids that like to poke on everything,  I have replaced a few over the years , I have one for my Cruze wagon to install when I get to it, ordered it from JC Wittney , to do it right you must remove the front and rear glass along with the back side windows , wagons are alillte easier, just the front glass unless you have a 79 or 80 , they use trim around it , and if you do i would buy the thick 1/2 inch insulation to put in the roof area, cuts down on the wind noise and better at keeping the car cool or warm, hope this helps and as for the snag I would trim any lose strings , if some one pulls on it it may unravel and the pain really starts , had this happen to me years ago with some friends bad (members of the hitler youth) kids in the back seat , they pulled a thread and undone half the head liner in the back before I knew it, last ride in pinto for them , I did not care if it was raining while they rode in the bed of my truck when their mom bummed a ride ,

I just had to do a HeliCoil repair to one of the hinges of the hatch.  When I touched the headliner to find the bolt hole, the 'liner tore about six inches.  Now that's gotta be replaced.  Sometimes old stuff can't be touched without "touching" other stuff.

Headliners are not only difficult to replace, but are expensive, and expensive to have installed. The biggest hassle is the fact that the windshield HAS TO BE REMOVE because the front of the headliner wraps up over the pinch weld at the top of the windshield, and is "wrapped over" by the windshield gasket.

In fact, the super strong 3M adhesive used to tack it to the pinch weld didn't hold it in my extreme Texas heat (putting in the windshield next weekend). I finally had to EPOXY it to get it to stay. It's not moving now.

Be warned also that the newer materials that they use for headliners is not nicely cloth backed like original material (according to my auto trim shop). This also reduces its ability to bond as well. I love my new headliner, it looks superb, but all being said and done it was a $500+ investment. Putting a Pinto back together ground up isn't as expensive as, say a classic Chevy, but it's still money....

BTW - If you DO replace your headliner, THEN is the perfect time to get some of that adhesive sound deadening material up under your roof (like FatMat with the black rubbery stuff and aluminized backing). The opportunity to cut noise here is great, and highly suggested.

Just my thoughts on this, good luck.

Chris

Headliners usually fail because they and their act get old. And for that matter, their audience gets old too. They no longer play at the big lounge, and even the big casinos. Typically they get downgraded to some off the Vegas strip casino filled with stale cigars and even staler stories.

 It's a sad life for old headliners. Their careers sag and they no longer have support from that thread they call "their audience." Eventually the (former) headliners come crashing down, torn form the lofty position they held and just become part of the planets human landfill.

Hope that answers your question... thought it is an odd one for a car website.

I see why you are whittsend