golf gti mk2 8v is group 14, with no no claims, aged 17 and male (i assume) you would be looking at £2000-£3000 easily tpft
at 17 i had a 1.1 fiesta - £1300 tpft
it will come down a lot with 1 or 2 years no claims tho.
the problem you will have is that no insurance company will want to insure you - i had great difficulty at 18 trying to get an XR2i insured!