I am 20, and my S3 sportback S tronic is on order for september. If I were to insure one now, it would be £1600 a year. By September I'll have another years no claims, who knows what it'll be, shouldn't be more, and I'm okay with 1600, so anything less is a bonus.
I am curious, are you buying the car in cash all in one, or monthly payments either HP or PCP. If paying monthly, I'd urge you to reconsider your decision. Yes, they depreciate. But if I tell you what I went through up until ordering my car it may help you somewhat...
I initially thought (contrary to yourself) that I could NOT afford a new one. So started looking at used S3's. I was adamant I wanted an 8V (obviously) and did not want to be buying a car of this nature with too many miles on it, the last thing you need is something going wrong, and hell, the previous owner probably drove it harder than he trash talks his ex, and who can blame him.
So for this you're looking around 22-25k for anything with an ounce of warranty left and less then 30k miles.
11.9% is what will kill you. Against 4.9% interest on a new car. YES you will own a new car at the steepest point of it's depreciation curve. But the used one that you want because it's depreciation has slowed down on will still be burning your money the same way depreciation does, only this time it's just to make some other guy rich, in the form of that monstrous interest rate.
If you're selfish like me, you'll get the new one. There was £10 a month difference between a used one at 25.5k and a brand new one at 36k. This was a combination of the lower interest, and the huge discounts you can get on new cars, that you'd never get on a used one in your wildest of dreams.
It is also worth noting the new one will be cheaper to insure, may have servicing thrown in with it, won't need to think about MOT any time soon, fresh brakes and tyres.
Is getting used really cheaper?