Well this is a list of things I have done to not only buy my Challenger but also to keep it over the years.
First of all the really big tip is live in the USA. It will cost you half as much to buy and maintain a car. However I live in the UK so that makes it a little tougher....
Save as much as possible by cutting out everything else. Even after 20 years I still spend as little as possible on other things. Forget about much of a social life outside of the car hobby.
Find a woman that does not mind taking second place in your life. It will ruin most of the relationships you have.
Get money any way you can. Even if you have to break the law to do it. Then borrow the rest you need. Also get as many credit cards as possible and be prepaired to be fighting to pay them off for the rest of your life.
In my case that was still not enough so eventually I sold a 40% share in my car to someone so they could share the bills and the cash injection got my car finished. In return this person took the car for their own use for 2 months a year.
That kind of worked for a few years but then I started to find it was causing problems. So as soon as i could afford yet another loan I bought her share back.
Current status. I now own three times as much on my house as I did when I bought it. However the credit cards are mostly paid off and I even have a small amount of disposable income for the first time in my life.
Good luck.