Welcome to FlyerTalk, MarkC1978!

While I agree -- as I usually do -- with AutoSlash's assessment, I just wanted to add a couple of options that you might not have considered.

1. If it makes financial sense to do so, you could book the rental car via a website where no insurance is included in the rate, and then purchase necessary coverage separately, from a third party, instead of from the rental-car company. Since you are a U.K. resident, the U.S.A. rental coverage offered by

https://insurance4carhire.com/

is an option.

2. If you have been an American Express cardholder in the U.K. for at least six months, and you expect to be renting cars in foreign countries fairly frequently now, you might consider applying for the Amex Platinum International Currency card, which offers not only coverage for loss of, or damage to, the rental car itself, but also provides third-party-liability coverage when a cardholder charges a car rental to the card. The card carries a steep annual fee, but if you're going to be traveling -- and renting cars -- often enough, you might find that the card pays for itself.