Actually, if you had taken that $30k for the Volvo and instead invested in Tesla stock, you could now afford a Tesla and keep your original $30k investment.

It's amusing to think about: By letting Tesla borrow $30k for a few months, they reward you with one of their cars.

Which happens to also (statisitically speaking) increase your lifespan by reducing the odds that you'll die in a car accident.

As an applied physicist wanting a better grasp of the mathematics I use, I'm working through Mathematics of Classical and Quantum Physics by Byron and Fuller. It's a Dover book, so it's inexpensive, and so far it has been enlightening. For instance, it uses the example of vortexes in a swirling bucket of water to help visualize the curl of a vector field.

Fire Hazard. If there were an emergency and the power went out, the last thing you want is haphazarly placed immobile objects (in the dark, no less) slowing you down on your way out the door.