Yes, I know what you mean; it does sound crazy to me!
I've always thought that the driver, including named drivers, would be fully covered with FULLY comprehensive insurance and I do believe that up until recently, that was the case; at least with Tesco.
This 'add-on' was not listed on last Februarys Tesco paperwork so, it's obviously just been introduced as optional cover at an extra cost of £38 which covers the driver (including named drivers) for up to £100,000 no matter who was to blame.
I thought their renewal premium was pretty good but, if I add £38 on, it's starts to become very similar to the other quotes that I've recently had online.
I'm now left wondering, if you are involved in a non-fault accident where the third party insurers are fully liable and, as the driver, you are injured, how much would you be covered for?
I will be calling Tesco to query this newly added option, prior to my renewal on the 11th February.