It absolutely is. I have driven without the rhino bars and the roof is quiet as you would expect without them. But noisy with them.
Initially, my front bar was in front of the safari windows and it was like a turbine. The dealer moved it back behind the safari windows on the raised bit of the roof and it reduced the noise. I also put the vortex strips on the front bar and that further reduced the noise.
However, I intend to move the front bar further back a bit (behind the raised bit on the roof) as it can still pick up more than I would like if there is a crosswind. Possibly move it another foot back (and then move the rear back similarly). That should reduce it down sufficiently.
Sounds like you have the N1 Utilty wagon version. That gets £190 tax disc where as the M1 car version is higher.
The only real difference between the N1 and the M1 is that the rear seats are further forward, more upright and have less legroom. And you are speed-restricted on dual carriageways and single carriageways. i.e. 50mph on 60mph single carriageway and 60mph on a 70mph dual carriageway. Some car parks have increased pricing for N1 vehicles over M1. However, if you have the glass rear windows, most car park attendants wouldn't spot it. And finally, the N1 vehicles are cheaper than the M1.
