Have a few questions as I am scheduled to rent for the first time in Europe in a couple weeks at the Heathrow Hertz location.

1. How important is an international drivers license? Required? Nice to have?

2. My rental rate is pretty decent, but the super cover and other insurances add another 100 pounds to the rate. How important are these? Are these sometimes covered by insurance companies?

Any other recommendations? I'm a hertz five star member, which probably doesn't mean much.