I don't mean to be rude but buying a GTI to drive slow is like going to a brothel for a chat, all a bit pointless.
Im 25 now, father, and I still can't keep my foot off the go pedal when the times are right, and I don't believe any 17 year old lad especially a bit of a petrol head wouldn't be tempted to nail a GTI at every given opportunity (and rightly so it's a GTI it's what they are meant to do).
Now I'm with the majority on this, mainly because I was the naive 18 year old who smashed my first car through a lamp post, smashed my jaw and leg up and lucky to be alive.
Now I wasn't driving like a bell end at the time, but would this have happend in a less powerful car with a little more experience, probably not.
My advice would be get the cheapest POS you can buy and insure to build up your no claims, save the money to go towards your GTI, mods and insurance (also look in to declaring mods, modified car insurance through a broker Is cheaper for me than the likes of go compare ect)
And I wouldn't even entertain a black box, how are you meant to entertain all the bitches with handbrake turns with a black box.
The strange thing is when I was younger all I wanted is a faster car, now I'm a bit older and have owned some quicker cars it's the slow ones you can drive right on the limit most of the time I miss the most, anyway it's about time you told us all to **** off and bought a loop Gti.