[Breaker]

Hi all, I have just purchased my first Boxster 2.7 on an 03 plate, this morning when I jumped in it and drove off there was a bad rattling sound like someone had tied on a baked bean can and I was dragging it along! I stopped and had a look but could find nothing loose and the noise seemed to be coming from inside the exhaust, has anyone else experienced this and if it is indeed the exhaust can anyone suggest a replacement?

Thanks in advance