[rkbharat]

Few more from my side, which I always keep on long trip, other than mentioned by other members:

1. Extra fuses, 2 for all numbers
2. Quick Fix/elfy, for any sudden break
3. 3-4 meter electrical wire.

Already Listed(Spare Tube, 12V air compressor, Coolant, Break Oil, Some Engine Oil, multi Tool Box)..

These are just few from cars perspective.