I'm going to install my first headliner 1965 Dart

Subscribed. I didn't know you were a early A body guy.
I like all of these cars! In 2014 I "restored" a 65 Barracuda and sold it (Along with several other cars and parts) to buy the Wife a 2015 Challenger R/T.
I still have a 65 Valiant convertible project.
This 65 Dart was a slanty, a prior owner added a 73 318 2 barrel. It is a mix of parts though. It has a later slip yoke trans which necessitated the use of a '66 steering column and shifter to try to make it look factory.
Thanks for the tips so far. I do have some small metal spring clips I can use for the sides, I didn't think of using them.Ebay 2.JPG IMG_2044.JPG IMG_2824.JPG