If you can't find it at any local shops, Summit carries it. Also available on Ebay, although i think i would rather go w/ Summit so you know you're getting a brand new can. Trick is to work slowly w/ Niteshades, as if you try to rush it it'll show in your work. Numerous light coats w/ wet sanding before spraying the clearcoat. "Search" for it, you'll find plenty of info.
A lot of auto parts stores used to stock that stuff. If someone sells VHT products they can get it for you. I would try to find it there first before I pay $10 a can for shipping from those crooks on Ebay!