There are a lot of GTA merchandising opportunities Rockstar could engage in, but don't. Action figures, for example. Another missed opportunity is in GTA clothing, which means other companies have to carry the load.
This shirt ("American Dream") is by label Gatsby. It could be more subtle, yes, but it does get the point across. Plus, they get bonus points for not only managing to barely escape copyright infringement claims from Rockstar, but from Wu-Tang as well.
You can get "American Dream" from Digital Gravel at the link below, it's going for US$31.
'American Dream' t-shirt by Gatsby [Digital Gravel]