At the end of the day...consider this...I am 29 and I pay nearly £600 a year for my 7 Seater Sharran...I have been driving for 11 years...no claims...couple of convictions
for minor speeding.
If you are 18, male and breathing...you will pay extortionate amounts for your insurance, for a good few years...don't think it will drop by much after the first year because the cost of insurance will go up in that year, thanks to all the uninsured drivers so you wont be much better off.
The only way to have cheaper insurance, is to go 3rd party fire and theft (although fully comp isn't always that much more and dont think you can get fully comp on your old banger, then be able to drive mum and dads Porsche or your mates Beemer, coz very few policies will allow "other cars" until you are over 25)...or to build or buy a Kit Car and get kit car insurance (dirt cheap) or, get a Citroen 2CV and just face the fact that its sh!t...so what, you will still be able to show the girls a good time...you have a car, make it look nice...you will have money to put fuel in it...money for drinks and cinema and clubs and fine lingerie...your mate who has a "nice car" will have sod all money, because he is paying out £200 a month just to insure it...then the cost of new tires will not put a smile on his face...once you go over 15 inch, they start getting proper expensive...
Save your money, drive sensibly and buy the time you are 20 or so, you will be able to get a nice motor...or build one as I say...or, Beetle...nice old one, no road tax due to classic staus, quirky...girls love em..and when you old enough...2.4 Porsche lumps bolt straight in