Rattle noise rear end

[eomak]

Hi, this has been coverd before but just wanted to get some better advise. I own a 2003 boxster 53,000KM basic and when it warms up to normal operatering temp. it starts to make a rattle tin, viberating nosie in the rear end area.Accerlatering,deccelater,at ilde reving engine its the same noise.Its drives and sound great until it warms up. Its at the dealers now and there trying to find the problem. I have full warrnty from the dealership,but i think the exhuast system is coverd under Porsche warrty for 7 years no?The dealership is a dodge and chrysler dealership.If it does have bad second cats. Porsche warrety pay for the items if found defictive?And dealership warrty well cover labour?And some peeps say it could be the heatshields?