2008 Mini Cooper s Overheating
 

I’ve been battling overheating issues with this vehicle for awhile now... I originally had a leak coming from a broken nozzle so I replaced the entire coolant hose assembly as well as the coolant tank I then ended up replacing the radiator and the thermostat to be safe. After replacing all of those parts I flushed the system out and topped it off and it seemed to have done the job I let it idle for about 30 minutes and there was no issue with overheating so I took it for a drive and after about 10 minutes of driving it started to overheat. Does anyone know what the issue could be?