Headliner question

[SHHR]

Has anyone ever steamed the late model foam backed headliner material immediately or soon after recovering one?

I had a customer who brought me a custom stretched Toyota Prius to make a headliner for. I cut two down and grafted them together for the added length and recovered with the new material. There is an area at the graft where I can vaguely see a seam showing through the new material and when trying to install this new 9' long headliner it buckled slightly along one edge and left a deep wrinkle in the fabric. I don't think either will be an issue with the guy since he did this car as a prototype to see if there may be a market for a 100 MPG car that can easily seat 7, plus it's an advertisment for his auto rebuilder business. Any way I think steam will pull these out, but am unsure as to what may happen to the glue I used (weldwood).
Kyle

[Rich]

Kyle,
Both the buckle and the graft seem to me to be the reason you are seeing a line through the fabric. If the substrate was perfectly smooth and you had a line, I'd say steam is worth a try, but since the line in the substrate is not going to change from the application of steam, I don't think it will become any less noticeable. Actually, it could even make it more pronounced.
If you do another, you might want to consider making each piece a little longer to overlap and wrap each piece individually.
Rich