Thinking about buying a Z

[mikecho]

Hello everyone my name is mike cho and im thinking of purchasing a 370z. I'm 21 and I work part time and go to school part time. Ive been saving up for about a year now and so far I have about 10k and I was thinking of saving up for another year and putting 20k down to buy a 370z and financing the rest. But Im hesitant to do that because 20k is a lot of money and I could just buy a cheaper car and invest the other 10k into a roth IRA or my 401k so I can have money when I retire. The other cars I were thinking about getting were a new Honda Civic Si (I use to drive a 03 Acura rsx and I'm familiar with the engine) or a new Subaru WRX. I really want a 370z and Im working hard to save up for it but I'm wondering if i should just buy the Si or WRX and invest the rest. Im fortunate enough to still live at home(dunno if thats a good thing lol) so i dont have to pay rent. What should I do ?