there are total 3 seals inside gearbox. if even one is leaking the gear oil leaks. but usually the leaking quantity is drop by drop. you might have this issue as well as axle seal issue (where inner cv joint joints meet gearbox). i had same issue with same car of same model (efi cultus 2008) and i had to openup its gear box and changed all seals inside as a preventive measure and it did the task. the seals were replaced for 1100 rupees by gear wala and 1000 labour to dismantle and re-install the gear box by mechanic. and then new gear oil.
