Hi I want to know if the gearbox used in the skoda fabia is derived from the one used in our fellys? Will it or the clutch fit a felly? Or is it a VW unit?

Any ideas?

Nope, totally different - or rather, the 1.4 petrol one is. The Fel gearbox is a Skoda one, I don't think it would have made it to the Fabia as VW had a full hand in its design and the Fel gearbox wasn't a strong point. Plus isn't the Fabia cable change?

Clutch you should be able to check from a manufacturer's catalogue. I'd be surprised if anything other than the plate is common, and even then...