Tachometer lights. It's a visual tachometer in light form so they can see when to shift. Seeing LED lights in your lower peripheral is way easier, and quicker, than trying to read a tach and see the actual red line; or see numbers if they use that type of tach.
Lots of race cars have those nowadays. I know Formula 1, Le Mans, and Super GT use them. And some of the higher-end road cars have them, too.