I was in US over ten years, have the same situation as yours. I agree with some guy's point.
If you but a used car you must take some risk even from friends or others.
DO NOT borrow money without giving a check to your friends and make promiss day to return. If you got problem to return the money at that time you must call them first then tell them why?? and when?? you can NOT delay more than 2 times!!!
Good luck to you!