Yes I believe you have misunderstood again by being way too focused on one part of my post and applying it to the rest. At no stage did I say use my personal situation as a blueprint to scale up and use as how we deal with the countries finances which is what you are kind of implying above(?)
I used that car finance example to basically agree with what you (and the expert Mr Koo that you sent a podcast link), that if you are suddenly totally fixed on the balance sheet and borrowing stops then the economy will retract quicker and deeper. Which again you have put above in relation to the 2008 crash. In my scenario it meant my spending power that would have helped other retailers was down by around £300 a month. Not everyone would have found themselves in that rubbish position but you can probably times that by thousands and then millions more that will tighten their belts to be able to weather any storm. So it's not hard to see why an economy tanks in those situations.
I don't disagree with you that by the government spending more and running a deficit in times of crisis will help the economy recover faster. I totally get that. Where my viewpoint differs is that this should not be an open chequebook with scant regard to the national debt. The risks are too great if it goes wrong, although that in itself is quite small, as it's unlikely that a country with the output of the UK will go bust if managed correctly.