If you're in the US and start traveling outside the US, you soon find out that every country may have its own ways. Renting a car can be interesting if you're relying on US credit card coverage. Luckily for you, the UK is generally considered covered with no real issues to face. Decline coverage at the counter as you would in the US, and you'll generally have no issues getting your car. Ireland is a notable exception, for many reasons. When I first went there in 2000, AMEX provided coverage there, then for a period of time, they excluded Ireland from their list of covered countries, and then they provided coverage there again. If you ever go back to Ireland, look closely at this thread, Car Rental Insurance in Ireland -- Very Confused. Although coverage is generally provided by US credit card companies in Ireland, it's a universal rule that you'll need written confirmation issued within a couple of weeks of your rental that you'll need to present at the counter for them to waive your need for coverage.

Even in the UK, though, your problem is twofold once you have your car. First, other than the modern motorways, Scotland and the UK have roads that were built long before the modern automobile. I've found the roads to be quite good, but it's intolerable at busy times inside the cities, and the rural areas can present challenges as well. Right-side driving is not always easy to adjust to, and as a result, you may find the occasional scrape with a car will occur.

That leads to the second problem. The damage discovered when you drop the car off at the end of your trip will generally require that you work through your credit card company. After you've left the country. And can no longer check the car for the damage that is claimed to have occurred. That makes it tough to contest much of anything--if the rental car company says you owe $2000 for damages on the car, you have scant resources for contesting that assertion.

Yes, insurance over there is generally two or three times the daily price of a rental. That doesn't mean the insurance isn't worth taking out. Get as much information as you can before going. Understand that the risk of damaging a car is probably higher over there than in the US. Realize that the UK/Ireland/other foreign country rental car agency has the "home court" advantage. And I agree with the advice others have given that renting directly through the agency rather than through a third-party website is preferred.

Written by someone with over twenty rental experiences in the UK/Ireland.