Trip meters

Back in my old rally days, we used a device called a HALDA. Its a swedish device that couples into your speedo cable- can be zeroed at intersections- and can be a double display with accumulative and intermediate distances. These are a mechanical unit, but there is also elecronic units these days by TERRA-TRIP.
Try a company in Sydney called 'Race & Rally"

Craig, use a GPS. The road junction becomes a "way-point", your trip goes into memory and you can backtrack if necessary. Mal T.

THanks guys, 2 good ideas - will chase both down.
We'll be using a GPS anyway, but had got used to the computer on the current vehicle.