For the second time, you have not read my post properly; I do not drive but I do live in Forest Hill and am familiar with the Sainsbury's. My concern is more to do with safety than damage to property but I consider instances of the latter to be of grave concern when considering the likelihood of the former.
There are several easy practical steps that could be taken to alleviate the problem but Sainsbury's, as the original poster observed, do not take responsibility.