We realized that people don't want to cover the same ground (as many as three times). So we figured we'd help out by driving vehicles to the other end of the track so that you can continue on your journey, save time and also save those hard-earned dollars.
Without Trackhopper, the Routeburn Track involves an 80 minute bus ride from Queenstown to the Routeburn shelter. After walking the track there is then a 3-4 hour bus ride back to Queenstown. If you wish to see Milford Sound, you would have to continue with the bus, or come back to Queenstown, pick up your vehicle then re-trace your steps back past The Divide which is only 45 minutes from Milford.
Trackhopper will save you time.