Not wishing to brag because we have all been there but I'm 28 & pay £268 fully comp (no voluntary excess) which I moan about, puts it in perspective for sure!
I remember paying £228 third party fire & theft for my 1st car (1.0 fiesta rolling on 15" Tsw's ha ha
) 11 years ago. Insurance seems to have increased significantly in the past few years & i'm surprised you guys are considering gti's at your age, is it worth the financial burden?
My 50 bhp was more than enough to have me screeching round corners & finding out I really had a lot to learn in the driving stakes at 17. sadly a few school mates were not so lucky & they paid with their lives
Have you looked at the insurance deals that fit a tracker & you can't drive between 11pm & 7am? this dramatcially cuts your premium down (not ideal I know!) You can lift the ban & pay for random times on the hoof if you need to use the car out of hours....