Baby Toddler I am 3 Years Old Cars Vehicle Transportation Birthday shirt 122CM-128CM (6-8 Years) 40% polyester Super comfortable boutique third birthday shirts in vehicle applique for boy toddler. Accented with an adorable car applique, this 3 Years old birthday boy tee shirt is available in all sizes so you can find the perfect fit. Ages 1, 2, 3 and 5 60% cotton 40% polyester. Ages 4 and 6 88% cotton 12% polyester.