Unfortally ever happened to me a few cases of people are selling my illustration, (especially GTR) without my permission and not even get in contact me.
If you are interested in buying poster, t-shirt and other products, they are ONLY sale on the websites:
(Also affiliated with their partners)
(Was the sale between 2015 and early 2016. The illustrations are a little different but they are exclusively licensed.)
Any print out these sites will not have the same quality.
Even these websites selling unauthorized, changed the illustration removing some Skyline GT-R versions.
For this reason I started to drastically reduce the size of my illustrations posted. For that do not occur the save images and change to sell them without my permission.
Thank you to all the people who are always warning about possible fraud.