There are many drivers on the road carrying only "cheapo" insurance - state minimum coverage. In most cases, this coverage is totally inadequate to cover the real world expenses of a car crash. You should protect yourself by making sure that you are carrying under insured motorist coverage (UIM) in the same amount of your auto liability limits. You should also have uninsured motorist coverage (UM) in the same limits too, to protect you in the case of a driver that didn't even get the minimum insurance.
I recently handled a case for a nice guy who had the misfortune of getting hit and badly injured by a bad driver that made an ill-advised left turn in front of him. To make matters worse, the bad driver had a tiny auto insurance policy ($15,000) that didn't come close to satisfying my client's $200,000+ hospital bill. Most people are shocked to learn that Arizona State Minimum coverage is only $15,000 per person, $30,000 per accident and $10,000 for property damage. Incidentally, these limits were set by the state when I was still in diapers - 41 years ago! Unfortunately, my client did not have under insured motorist (UIM) coverage and his case turned into a salvage operation.
Skip a couple Venti Macchiatos, eliminate your rental car reimbursement or just pay a few dollars more, but don't forget to carry Under Insured Motorist and Uninsured Motorist Coverage in the same limits as your liability coverage.