Bear in mind that the hood in is the forebody region,where it is attacking the air,and in a very favorable pressure gradient,with the surrounding flow 'holding' the boundary layer to the car.You'd never see separation there.
Where you'd need help,is in the aft-body where there's no reason for the air to remain attached unless the turbulent boundary layer could get an extra injection of kinetic energy from the outer inviscid flow.
Scientifically,the hood has nothing to do with fuel economy,only the back of the greenhouse (C-pillars and roof/backlight header area ).
You can see from the Golf/Rabbit that the flow around the hood and over the roof is fine.And your car is 'cleaner' than the VW
The challenge is to keep it stuck over the aft-body.Short of a streamlined body,VGs could help.