Don't bother, if you change it from standard your insurance will rocket,insurance companies do NOT downgrade car specs,it's not a motor scooter,I would find low insurance group cars first then buy one of those,the one you are thinking of is low anyway,you won't be able to reduce your insurance at your age unless you take more training,your stuck with it until you age a bit,if the belt has gone don't touch it,it may cost you a grand to fix it and the car is scrap value only.Get the lowest insurance quote on any car then save up and buy a runner.Tough world I'm afraid,if you have a full licence at 17 you'll get there.BEST of luck,don't give up.
Rich
January 2010