Insurance for a test drive

I am debating changing car and was wondering about insurance when taking a test drive.

When I have gone to large dealers they take a copy of your licence and the test drive is covered by their insurance, has to be accompanied, etc, etc.

When I have spoken to smaller dealers they don't give a straight answer on this.

I looked at my insurance policy and it covers DOC 3rd party only but says nothing about covering a test drive.

I will call the insurer tomorrow to see what's what.