Is Aviva Driveaway car insurance any good?

I recently purchased a used car from a private seller and did a HPI check for the vehicle online before finalising the purchase.

On the bottom of the HPI report there was a 0800 number to call Aviva to get '7 day free driveaway insurance'. In return I have to provide my details (obviously) and also get a non-obligation annual car insurance quote from them should I wish to continue with Aviva car insurance.

I have been emailed the 'insurance cover note' for the '7 day free driveaway insurance'.

I need to know that it is driveaway insurance policy sufficient for the 7 day period or should I go ahead and sign-up of an actual annual insurance policy straight away.

Interestingly, the driveaway insurnace policy T&C's say that it is available only if the customer does an HPI check for the vehicle and then goes forward with the purchase of the vehicle, But, I was NOT asked for the HPI check reference number when I called aviva, so any one can call then up and say I want a 7 day drive away insurance as I have done an HPI check (even if they have not) and they will get the driveaway insurance.

This raises a question in my mind that is the driveaway insurance any good or sufficient?