I've got mine running behind the dash, in through the removable panel at the back of glovebox, where it sits nice and safe and out of sight, until I need to use it, then it sticks out the top right corner of the glove box (which closes perfectly well thanks to Renaults lovely fit and finish!) and plugs into my iPod that then sits very nicely in the clock cubby hole, where it stays even under enthusiastic driving. The best thing about it is you can plug ANY auxiliary device in there, not just an iPod, and it cost me £10!
I drive my Trophy down the motorway every morning to work. Some times I relax and take it easy with the cruise control and some times I fly down the motorway (depends how late I am). I would never say the ride or the road noise were normal.
I owned a Mini Cooper before my Trophy and have to say the Trophy is much quiter at all speeds and it rides a lot nicer thanks to not having run flat tyres. The tyre roar at speed in the mini was rediculous which is probably why the stero used to increase in volume at speed. Plus the cabin doesn't creak and rattle all the time. Was a bit nervous about changing to the Trophy but its definalty the best car I have ever owned.