The Retrotrips themselves do not have the facility to count backwards, which is one of the many features
that make it so popular in the historic events.
Retrotrip Back-Tracker, when activated, stores the distance you drive to correct your error, then when you are back on the correct road, a simple flick of a
switch and the Back-Tracker counts out your incorrect Miles/Kilometres, not allowing your Retrotrip to count up until it has erased all those incorrect Miles or Kilometres you gathered.
Also exist in Plug Kit Version Connects directly to the 4 pin plug & Socket of the Plug Kit Retrotrips (second picture).