I too use Quicken religiously, though not so much to control spending as to simply be aware of it (yes I should budget but it’s just not my thing - my control mechanism is intrinsic based on my known state of the financial union gained from keeping track a couple of days a week).
I’m debt averse, so the car financing thing seems crazy to me. We have lotsa cars w/ two teen drivers so our expenses are high; but the newest is a 2007 with 164k. I do the vast majority of my own auto (and home) maintenance too, but it’s gotten bad to a point of frustration when I have to pay someone else (I guess I have a problem....).
I’ve also bought furniture and flooring on zero-percent-for-years deals and I always want/need and do get them paid-off early. Still paying on my one foolish foray into a 401k loan when I needed a cash position a couple of years ago. That’s not really a debt but is driving me crazy too. I’m hesitant to pay it early as I’m feeling the market is due for a significant pullback so I’m DCA'ing it back in with monthly payments, but man do I want that off the books. The mortgage is about the only debt I can take; refi'd to a 20 yr a number of years ago so the interest portion of our payment is quite palatable.