How do people finance 70,000 odd $$ to purchase a new car

[XARATE]

Ok this is going to seem like a stupid question, but how do some of you guys go about getting finance for a new car?

Im looking at getting a second hand FG 335 GTP in white with a six spees manual, but im looking at the financial aspect and i cant understand how i can get such a loan with any real assests. I hoping someone can advise me on if my financial position looks good from a banks view. I dont want to go for a loan if im going to get knocked back.

I currently have a 6speed manual 2005 ba xr8 which i could sell privately for around $18,000 and my really my only other assests of any value is approx $10,000 in tool/toolbox.
I also earn $630 a week after tax (auto elec same employer for 5 years) with $200 a week going towards a personal loan of $27000 over the next 5 years (car and medical bill)
Ive got no rent to pay as im at home looking after my sick father and i have a perfect credit rating (one credit card thats emergencys only and two previous loans payeed of well before that were due)

My xr8 is getting a bit on and want something with bigger balls, more stopping power and more modern, i feel i can afford to buy a FG but what do you guys think? Will the bank be in my favour? Im told by people i work with that i may not earn enough?