Was the Tesla Starman suit pressurised? If so, is there a good link to substantiate this?
It has the ability to be pressurized
It certainly looked like it. Pretty stiff, not like when astronauts were in it for Crew Dragon (suit unpressurized then). Of course, that probably didn’t last indefinitely. Suits have a leak rate and I’m not sure it even had more than a relief valve on it.
If I were SpaceX, I'd have 'pressurised' it with expandable foam, possibly with a poseable armature inside to minimise limb straightening. Cheap, no additional support hardware required, and avoids the chance of an embarrassing visual of deflated - or displaced - suit being revealed when the fairings open. Vacuum outgassing, UV degradation, materials interaction, etc are not concerns for the limited lifetime required and purely visual functionality.
A not verified but plausible account:
Inside Starman’s space suit is a poseable, full body, foam dressmakers dummy. It went through vacuum chamber testing to make sure it wouldn’t blow up and look funny. The inside of the helmet face shield is painted black so you can’t see the dummy’s face.
Starman’s hands are stitched to the door and steering wheel with thick thread. They did pull tests with a tension gauge to make sure it was secure.
So it looks like it would have been but probably wasn't. Thanks everyone.