Most of these posts have been (in reply to the original question) UK-centred. North Americans (and perhaps others) will often find that their own driving insurance will also cover them in a rental vehicle. This was once the case in the UK as well, but has been quietly "stolen back" over the years.

I have bank accounts in various places :-) and although resident in the UK, my BA EC is US-based. I have credit cards based in various countries, and the US and Canadian cards both offer CDW cover (basic cards might not) with some variations of excluded countries. I once tried to use my Bank of Montreal MasterCard to book a hire car in Ireland (on most card issuers excluded list, along with Jamaica and Israel) but couldn't do it because the hire company wanted to put a hold on the card for the entire value of the vehicle - more than the credit limit I had thought sufficient.

That car ened up damaged (hit while parked overnight) but the repair bill was less than £100 (pre-Euro days). My experience is that western European hire-car accidents cost a lot less than North American ones.

I would suggest asking very carefully what is included and what your overall risk is. In some cases, hire car counter staff try and suggest that declining additional insurance leaves you responsible for the entire vehicle cost. It's not impossible that this could be true - each country, company and perhaps even location are different. Ask.

Despite being Avis Preferred Elite I am finding that Avis rates are shockingly poor this year. I have a three-week rental scheduled in New England next month and Dollar is one-half the price! Dollar also don't saddle you with some horrible Buick. Over the years, I have been happy with Avis but they are slipping badly.