Speedster: Did you buy your car brand-new in 2010?
I bought mine in 2010 and all the cars a I saw on the lot came WITHOUT that little parking stop curb scraper...erm Lip spoiler.
If indeed you got that stock on yer brand-new GTI, that is lovely and you got lucky..I suppose I would flaunt it too if I had it./
As for aerodynamics, an underengine/ front underside tray is way better for pushing air to the radiator and shaping air underneath the car than a small plastic trip piece ahead of the radiator and in the middle of the front nose. Your 2010 prolly has an underengine tray so you're good there too and you prolly have much more downforce and radiator cooling at the front than most of us above 70 mph.
It's not about air going under the car, cos air will go under such a "tall" car regardless of a little lip spoiler, it's the shape and direction of that air that is much more important in terms of stability and downforce. A set of AUdi S3/ TT undercar trays and control arm air diverters are the most effective pieces for downforce'/ air shaping and yes, they fit the mk6 Golf. (since you're deep into downforce and all)