Well you certainly can, however the insurance waivers some rental companies provide can be as much as £20 a day. £20 with us however could get you a policy for 5-day duration in Europe at a cost of 11.48 for example but the choice is down to you.
The Guardian newspaper noted that rental related extras is where the car hire providers make their profit as last minute upgrades and extras such as damage waiver are charged at a premium - The Guardian - 10 ways to avoid car hire costs and it is for this reason that companies like ourselves offer car excess waiver protection.
Even with inflated rates, the rental companies policies often have exclusions like windows, tyres, undercarriage and the roof whereas purchasing this protection in advance you will find a more comprehensive level of cover at a much more affordable price, our options when buying car excess insurance details the choices you can make be it in advance or at the rental desk. Basically this means you pay more for less by taking out the rental providers insurance extras offered at the rental desk on collecting your vehicle, it really does pay to do a little research somethimes.