You are searching for mystical causes and mystical answers to a situation grounded in plain reality. A rationalist will point out that random chance put you wife into the ditch, and that's where your problems began. It has nothing to do with it being a Nissan or any other brand. You are left with a physical conundrum that cannot be directly or indirectly solved through mystical divination, and you are beating yourself up over it. Takeaways:
1. Know your limitations. Throwing good money after bad with your fingers crossed is an indicator when you have crossed this line. If you are in the car business, an electrical expert is a valid resource.
2. Using what you characterize as a business investment for personal use is going to skewer profit odds against you. I know a lot of people do this, but it is a crap shoot because of that pesky random chance thing that reality exists in.
3. If one car is causing you life-doubting angst, dump it cheap and now. It's just a car.
4. Trees fall over every minute of every day. Instead of assigning a mystical purpose to the one that missed the mark, try cutting back every tree within range of your driveway, 'cuz the next one might smoosh your tow vehicle.
Not trying to bust your chops or your beliefs, just giving you a different viewpoint.