Samantha, as usual, reset TRIP B at 10,000km (every 10000km for cars with kms). Interestingly - the SAVINGS didn't reset - whether it's for the life of the car, I'm not sure.
OK, thanks - hopefully it doesn't get to $9999.99 - if it does, either the price of petrol has skyrocketed, or I've kept my car much too long.