Callahan Auto Parts T-Shirt. Callahan Auto Parts shirt. Vintage Distressed print. The shirt color is a very UNIQUE Leaf Green T-shirt with white print and a natural color shirt with kelly green print. You don't want to get into a horrible car wreck that is so bad that the new medics can't even stomach and end up going around the corner to puke their guts out, just because you want to save a couple extra pennies. Listen, you went to college for seven years, you're smart. If you want auto parts you can trust, you want Callahan.