This is something of an older article, but may still be worth considering.
The only ones I'm familiar with, having had direct relationships with them, myself, are AAA, and Geico. You will probably want to research some other providers, if you don't already have sufficient coverage.
While not sufficient for professionals, Broad Form may be of interest, for personal use. It is sometimes known as "owner named coverage." This means that only you are covered, not the auto. If you are single, this may be sufficient. Also, if you have more than one car, it can be helpful. Usually, you need each person to be insured, and each auto to be insured. With Broad form, you're insured, no matter what car you're driving. The car won't be covered, but that may not be too much of an issue. The only other issue is that it's only available in some states. The only ones I can think of are WA, ID, MT, and NE. I think DE/CT may be, as well, but not certain. It's not as easy to find out, for sure, either, but may be worth investigating.
One more thing, if you're financing a car, it won't suffice, as the financer wants their loan insured, and maybe, if you're lucky, you'll get coverage for a car in the deal, too.