Compound charging is quite complex both mapping & packaging.
There's several ways of doing it:
1) Use the charger & turbo independantly don't really gain a huge amount here- better off sizing a turbo properly.
2) Charger & large turbo, with an electromagnetic clutch on the charger- to cut out when the turbo boosts.
3) Charger blowing into turbo
The boost system would have to be well controlled, and the intercooling would take up a fair amount of room, mapping is quite complex, and the transition period between charger and turbo would have to be seamless.
All in all it's quite a complex job, and you're adding more components for the sake of it- with modern turbocharger design you can have something that will spool at low rpm and still maintain good top end power.
As for 'shitty polos' type in 'Polo vs RS4' into youtube