I just bought some to make some spats for my car. The only place that had it was Regal Plastics in Austin. 836-3629. All of the sign shops told me to call them.
I have a few feet of it left over, so if you can't find any let me know and maybe we can swing a deal (it cost like $1 per foot, so there wouldn't be much dealing going on
).
Darren