Honestly, unker never needed any formula when i last purchased my 2010 Vios. My last car paid off and traded in with new car. Continue to another 9 years of installment, this was when unker was young that time and has no family yet. Now fast forward car installment done and never had the thought to upgrade unless or until we are blessed with a child.

IUnkerO all those formula is just guide lines for current generation to look good and know very little about their own finance, but to unker when you need it you will have to get it. Be it recon or 2nd hand, priority takes precedence and anything else is a "want" for unker. Also unker view car as a tools and not more than that.

So to answer TS questions, unker willing to use this "formula" for my next purchase of family car "6mths x salary" max and wont be putting extra 1cent as down payment and take perhaps 5-7 years of loan.