Personalized 2nd Birthday Race Car T-Shirt. Whether you're throwing a race car themed party or just want a fun outfit for the birthday boy, our products are the perfect choice. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.