i intend to create for the car a hardcore (approx 50cm then small stone on top) drive. Can you get away without using geo tex membrane, A JCB will remover the grass.

Geotex will slow down the appearance of weeds but will not stop it. Geotex stops weed growing up from underneath and will stop mud coming up through what is on top. Sooner or later weeds will take root on the 'what ever' is on top.

Are you actually going to use hardcore or some other type of rubble / stone. If the hardcore is yours then OK otherwise I would expect to find all sorts of rubbish in it.

Do you really mean 50cm ? nearly 2 feet ? Unless you have a lot of hardcore to loose that is overkill. 15cm - 20 cm is enough.

If it really is 50cm then IMO you don't need the geotex !

The usual makeup for drives here is limestone chippings, as dug for the base and graded for the top because it is angular and therefore stable.(Limestone chippings = murva). Gravel is not used much because it moves around (because it is round) (gravel = soder (pronounced shoder))

Yes about 15cm, I will use geotex and I will ask the local stone supplier about "murva" if he does it. The small stone I refer to is angular and not round.