I have always thought coming up a hill gives that vehicle right of way, but if there is traffic parked all along the road going up hill, does that give the vehicle coming down the clear side right of way?
Depends on many things - if the car going uphill has already committed to overtaking then that still has right of way.
If the vehicle going uphill is a heavy vehicle such as a large lorry or crane than that has right of way.
Otherwise the vehicle coming down has right of way.
My OH had already committed to going uphill and nothing was coming, then a 4 x 4 appears from nowhere and decides to keep coming by then OH has nowhere to go, (cars parked nose to tail) on his side of road.
I wasn't questioning your driving ability, merely pointing out what the Highway Code says. Perhaps I could have worded my answer a bit better. There is no give and take on the roads and people pass their driving test, then drive like maniacs. When I learned to drive, we had a saying "it is better to be five minutes late in this world, then fifty years early in the next."
If you were already on the hill than the 4X4 should have given way. From what I see on the roads these days and elsewhere, the phrase should now be uncommon sense.