So sorry to hear there's been some confusion about our Shaka Guide tours and app. Shaka Guide does not work with Apple Car Play because Car Play requires a constant active internet connection while our tours are designed to work 100% offline. We made our tours so because there are a lot of areas on the island that has very poor to zero internet service.
We have 3 variations of our Road to Hana option, all with different approaches and directions. For what you described, it sounds like the Classic Road to Hana tour would be the perfect choice but it seems you've chosen one of the other options.
Kindly email us at aloha@shakaguide.com if you'd like to discuss this further or to get a refund. Mahalo!