Questions, bugs or feature requests: lorenz@bohlander.de
CarPlay support requires an entitlement that Apple must approve. Until that is granted, Tripmeister runs on iPhone and Apple Watch only.
Allow Always for location access in iOS Settings → Privacy & Security → Location Services → Tripmeister. With “While Using” the app can only measure while it is on screen.
Use Calibrate: drive a zone of known length, then apply the correction factor. It applies to both trip odometers immediately.
Results → export as GPX or CSV, or sync a stage to Strava.