You have to look at the cost vs. risk.
For me, when I bought the 13 year old car, I called my insurance and chatted a bit. For a $6,000 car, it would cost more over a few years for full coverage than the cost of the car itself. I added the basics, and did not get replacement coverage. In 27 years of driving, I've had two accidents, only one of which was my fault. I expect I'll keep the same track record. If someone demolishes my jetta, their insurance will pay, not mine. If i demolish it, I'll get salvage value and move on.
Calculated risk.