Willy Wonka Costume Diy . This diy willy wonka costume is made up of pieces that you may already have in your closet, plus a few things that can easily be found at your favorite thrift store. Whether you want to celebrate the day in purple velvet like willy wonka. Willy Wonka Costume Idea from meaningfulmama.com Trunk or treat car costume 44. Use the eraser tool to erase the hat and the “bar” word out of the logo and erase the “wonka” out of the other logo. Our (mostly) diy willy wonka halloween costume.