I've been reading the sections in the manual regarding battery charging and jump-starting the Fabia, it says you connect the negative jump lead to the 'grounding point' (Seems to be a metal tag next to the battery) rather than the actual negative battery terminal

 

-- why is that? - there seems to be some kind of sensor between the earth point and the battery

-- If I wanted to help someone else by jump-starting their car, should I connect the leads the same way?

I believe it's to reduce the risk of sparks igniting the hydrogen that can be emitted from a battery that's charging.

2 hours ago, FollowingGhosts said:

I believe it's to reduce the risk of sparks igniting the hydrogen that can be emitted from a battery that's charging.

 

That is my understanding as well, the lump that is now between the battery -VE and the car's metalwork will just be a very low value high wattage resistor I think, either 0.1ohm or 0.01ohm,you will see that it has a "tap off" at each end to supply the BMS with information about what charge/use the battery is getting/giving.  So, I'd play safe and just continue to keep away from the battery -VE when giving a jump start or charging that battery.

 

Or, just don't risk your car by providing a jump start to anyone, if you feel the need to be able to give someone help then spend some money and invest in one of these compact "boost starter packs" - that way you will not be risking damaging your car, by the way, I never given a jump start for maybe 20 years by using any of my cars batteries, I'd only ever do that with my old style booster battery pack which is quite large and heavy.