Gentleman Gentleman Gentleman
Regardless of the type of backing you order, a steam iron is nearly a necessity to get that stuff all worked into and pressed into the corners and curves.
I discovered this purely on accident. My mother is an avid quilt maker etc., she has some pretty high dollar clothing irons and the one with the teflon bottom became my friend for the day. hehe
Just don't tell your mom that you're using her $400+ clothing iron for auto interior. hehe The cheapos would have worked as well. I didn't know one from another and this one looked legit.