Yeah, that´s a fantastic calculation. You just missed the most important thing, that will totally wreck your numbers. The OP talked about a time frame of 2 -4 years. So, the reality will be minimum the double of your 8 years. In reality minimum 150k bath over 12 month or as high as 300k baht over 12 month if only 2 years.
So, there we crashed and burn real good! Totally unrecoverable man! Just wreck it, Ralph! ????????????
I know, now you are going to say that the second hand value will be much higher. So, will the problem with selling the car, whatever value you wish to put on it.