I was in the same position as you 13 years ago, I ended up waiting till I was 21 to buy a tt6 and I'm pretty sure that even though I wasn't completely reckless in the car,(I had respect for it from day 1) if I had paid out a stupid amount for insurance at 18 I'd have crashed it, been banned (most likely) or worse. N/a or tt its too much at that age on the road and a waste of money, it's not about driver skill or anything here, but the urge to put your foot down and do stupid things takes over as a teenager let alone your twenties.
If I could do it all again, I'd have forgotten the supra for now, saved the majority of the money and bought something rwd for track use/drifting or a lower powered rwd to replace your corsa(eunos or bmw) and don't spend ££££'s on the insurance. It's not what you want to hear but I've been there and done it, I seriously regret not working my way through the ranks of rwd cars and starting off with much cheaper cars.
Though my best advice would be to not bother with a second car, keep your 10k locked away till you're 21, save £400 and do a drift tuition day at santapod, do that a couple of times, then reassess then, there's no rush.
Cars will take over your money from this age, I've wasted a sh*t load and it's screwed me completely now,save towards buying a property where you can have a nice drive/garage to play around with cars on for years to come
Last point as I really don't want you to make the same mistakes as me, if you've not saved that 10k yourself then you'll have no real regard to that sort of money in your account and how long it takes to save and appreciate it, I wish I had given myself the challenge to double it before spending a penny.