Rear light gasket leaking

Hi guys.

Have been getting lots of condensation in my car and I've found out it was due to water in spare wheel well due to the gasket on the rear light leaking.

Has anybody else had this problem? The gasket seems to be made from foam so just holds the water then leaks when saturated. Nissan want about £27 for a new one so trying to think of another solution. Any ideas?