How about a personal guide?

A Road to Hana Audio Guide is the next best thing to having a real, live guide in your vehicle. Hana Picnic Co. have a step by step Audio Tour CD to guide you along the Hana Highway and make sure you don’t miss out on any of the wonders along the way! It sets a reasonable driving pace, and prevents you from attempting to set any land speed records IF you adhere to the Road to Hana Audio Guide’s timeline. Pick one up when you are getting your lunch and supplies.