Driving underinsured saves money until you or someone on your policy causes an accident. Insurance companies routinely sue people for repair costs, totaled vehicle value, PIP and Med-pay amounts that are not covered by your policy. Price out the cost of a Tesla, or any electric car, SUVs, and pickup trucks and you'll quickly find that a 25,000 property damage policy wouldn't even fix the front end and guess who ends up paying the difference?

I would also have a substantial umbrella policy if you own your home, have other assets, are the sole breadwinner, have a young family, etc. If you were to severely injure or even kill someone, the claim could be worth millions (the same if you were severely injured or killed by someone else). Driving with a basic policy will save you money - until it doesn't.