I don't have any problems with noise from the panoramic roof (unless something falls on it). As to the exhaust/muffler sound, I,too like it. It doesn't sound like a sewing machine, like so many other little cars do, but isn't obnoxiously loud, either. As to the speakers - I have a relatively destroyed sense of hearing, when it comes to quality vs cheap, having worked around jet engines in the Navy for 5+ years. However, the speakers in the door just don't quite get me the volume I need to overcome the road noice when my windows are down. To that end, I am installing a set of 4" speakers in the back (and will post pics when done), to help with that.
Other than that, if you drive with the windows up, and still don't like the noise level (after you have gone to the dealer to have that roof noise looked into), there are some tutorials and other info about adding noise-deadening material under the carpet - might be worth it for you.
Cheers!