Unless I missed it, the article did not really touch on merchandising to much. You would think the top tier NASCAR drivers would make a ton on T-shirt sales but that is not the case. Per this article, The bulk of it goes to fanatics, the operator, and then the tracks. This is why several NASCAR drivers have their personal line of racing shirts. Those usually are only sold online and don’t feature the cars.. Larson even tweeted about making more on T-shirt’s at the dirt tracks.
I would assume IndyCar is similar. I am not sure I care about f1.
https://nascar.nbcsports.com/2017/07...h-for-drivers/