Three things spring to mind 1) The rubber seal around the trunk lid is distorted or split 2) The water could be coming in from around the rear light units. 3) The trunk lid catch needs adjusting to pull it down tighter. Mind you, I'm from England so I can only refer to the assorted rubbish that we are forced to buy over here. Best wishes! PS Over here a trunk is called a 'boot'......a trunk is what is fitted to an elephant as a nose replacement. Wonder who's right? :)
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