BMW Repair: 2004 318i E46 exec idle rumble, steering wheel, drivers seat

Question
Hi,
I'm the proud new owner of a 2004 318i E46 executive. It's an auto but also has sequential manual.... It's really lovely. I've only been driving it for a week so I don't really know what's normal.

It drives beautifully but when sitting at the lights there's a kind of rumble/vibration. I feel it most under the drivers seat and in the steering wheel. It feels odd because it's a bit inconsistent.

I'm using fuel rated 98 and the dealer serviced it before I picked it up. The service history seems to be in order.

I don't know if this is something I should worry about? I have a three year warranty so I wonder if I should take it back sooner rather than later?

Thanks in advance for your advice.

Cheers.

Answer
If you have questions and the vehicle is under warranty you should go back and discuss that with the dealer.I know the vehicle is new to you but it is actually 7 years old.So being on the safe side discuss this with the dealer as the car shouldn't rumble and vibrate.