Except it isn't really a renewal that ALA offer. The further cover they offer at the point of expiry is a Retail Value GAP insurance policy based on the depreciated value of your vehicle at the time of taking the additional policy out.
The company I linked to in my previous post will offer you...
http://www.GapInsurance.co.uk will be able to provide you with a form of extension/renewal of your Invoice GAP insurance policy for 12 or 24 months regardless of who you bought the original policy from. Though you have to buy it before your original policy expires.
All other companies that will...