OMG, I seriously regret asking for advice in this forum.
Why not go and ask for advice on a Supercar forum? Although I rather suspect the reception you get will be even worse. I am lost for words that you appear to be suprised with the reaction you got here.
The very fact you think buying a 150k car is like buying any other car demonstrates quite clearly that such a car is completely unsuitable for you.
You can't go to Tesco in a 150k car, not very effectively. Well except perhaps an CL65, but thats about it.