I've got 2 paint markers on most stuff already, just so that it looks like it must have come from North Geelong production line (pretend it was locally assembled) a few weeks ago.
Car builders stuff sticks like...., especially with the hot air gun getting it soft beforehand, but man is it heavy.
I'd bet they would stick fine on the roof. I used a little 100 mm roller handle without the roller to shape it into the floor ridges. Maybe dont go nuts like I did and put it everywhere. Just a few pieces to stop the natural vibration 9 or to seal up the weld lines ..:))
You can often buy it cheaper at Repco with RACV/members discount, than you can online from CB.
Santa is bringing me a pair of Carbuilders "finally a decent pair of scissors" for $40, for fathers day, intime to do the seats with.