Insurance when you first buy a car

So here's my scenario....  My husband owns a car and we're both on the insurance policy.  He bought our first car (on ebay!!) over here before we moved so he got insurance purchased immediately.

But now we want to buy a second car.  I am looking at buying a used car from someone(classifieds, gumtree etc.) However, if you decide to buy it can you drive it home before you have a chance to buy insurance on it?  My guess is no, but I wanted to see if anyone had experienced this before. 

Back home I thought most car insurances gave you some sort of covered grace period to give you time to add it to you policy....

In addition we are looking to change insurance policies.... Anyone have any recent recommendations for good value insurance? 

Thanks!

So here's my scenario....  My husband owns a car and we're both on the insurance policy.  He bought our first car (on ebay!!) over here before we moved so he got insurance purchased immediately.

But now we want to buy a second car.  I am looking at buying a used car from someone(classifieds, gumtree etc.) However, if you decide to buy it can you drive it home before you have a chance to buy insurance on it?  My guess is no, but I wanted to see if anyone had experienced this before. 

Back home I thought most car insurances gave you some sort of covered grace period to give you time to add it to you policy....

In addition we are looking to change insurance policies.... Anyone have any recent recommendations for good value insurance? 

Thanks!

Someone mentioned GEICO, maybe because they are an American company setting up shop in the UK and they understand no claims in the US and they gave someone here a good rate then someone else got a lousy rate?? I think they said when they talked to them on the phone they were talking to an American on the other end.
I'm sure there are others.

You can get 7 day policies that are designed to give you time to find permanent ones. 

I had a 7 day policy and stuck with the same place, but you don't have to.

For example (not what I used):

http://www.aviva.co.uk/driveaway/