For Team Sonic Racing, the Sega Shop is offering something all-new: Personalization on an official item! How unusual...but is that a good thing? Either way, you can choose from a jersey of each of the 4 teams in the game.

Each has the team's colors, plus accent color for the edges & sleeves, plus a 'checkered flag' fade for the bottom. The shirts are not made of regular cotton/tee material, they're probably a lycra blend of some type. The back of the shirts in the photos display "Racer Name", so you could put your name, or, for value later, add a character's name instead like having "Shadow" on the Dark Speed one, or "Amy Rose".
It's a neat enough concept, but the combination of personalization and a more exotic fabric makes the shirts fairly costly at about 40 dollars each.
*Why might it not be a good thing?
Because bootleggers LOVE personalization. They use it as a huge tool to fool parents/grandparents into buying items with stolen art all over them. Some people love personalization, and will buy fake stuff just to have their name printed on it, as well. So: personalization was usually a very good indicator of fake stuff, because no official company bothered to offer it. (With the exception of a few party goods and possibly 1 mail offer exclusive) It's costly to do, and can be difficult, it also takes more time for a company to make money doing it. There's nothing inherently wrong with personalized stuff, but it just means to be double-sure to check for authenticity.