I have had 2 cars both vs and they both over heat when stationary ie. at a read light
Are you loosing coolant?
Mechanical or electric fan? Check the viscous on mechanical or that the electric fans function.
Edit: pretty sure all vs's have electric fan. Let it idle with the bonnet open and check the fan kicks in just before temp gauge goes past half. Running with the heater one whist driving might gain you a bit more time til it overheats.
Your thermostat could be sticking shut?
Your radiator could be partially blocked restricting flow, thus reducing cooling at idle.
Your waterpump could be on its way out and not working as effectively.
Or it could be as simple as having air locks, have you recently drained the coolant?
Check your radiator for leaks/cracks or could be blocked
Change your thermostat
Check all your hoses/clamps arnt leaking
I reject your reality and substitute my own.
I took the thermostat out and still did the same thing. I will check all the hoses and radiator i think?
You could also get the radiator and cooling system pressure tested for leaks.
My first car did have a cracked radiator but the car I own now doesn't and they have the same problem.
Just a photo of it for fun haha.
as m1lky has said get a pressure test.
Did you bleed the system with the heater tap fully opened?
"Success is the ability to go from one failure to another with no loss of enthusiasm" Sir Winston Churchill.
My VS II Berlina Wagon
MY12 II SV6 Sportwagon
Yeah you have to make sure you bleed the system I usually do it over two fan cycles with heater on full