Car rental is one of those purchases where the headline price is rarely what you end up paying. The keys to a good deal are understanding the insurance, the deposit and the fine print on fuel and mileage.
Rental companies push hard on their own excess-reduction cover, but you may already be covered by a travel policy or a credit card. Check before you travel what your card or policy actually covers, then decide. Declining the extra cover usually means a large excess held on your card if something happens, so never skip it blind.
Return the car with the same fuel level and a few minutes early — late returns and refuelling fees are where rental bills quietly climb.