Scirocco Central

Only had my 2009 2.0 Tsi a few weeks and it is going in under warranty next week as exhaust system warning light came on yesterday. Not sure what the problem is and difficult to tell if exhaust note is normal or not having not had the car long. When I am rolling at low speed with foot off the accelerator there is a rumbling noise coming from underneath the front seats causing a vibration in the passenger side seat bolster next to the gear stick. The car has been doing this since I bought it so I have mentioned it to the dealer and they are taking a look next week when they sort exhaust light. Does anybody have any ideas as to whether these two problems might be related or it could be something else. If the vibration didn't seem to be under the front seats I would have said the noise sounds like a wheel bearing on its way out but after the exhaust light has come on I am thinking it is maybe a blowing exhaust or something similar.