Hi there, I can't remember there being a great noise from the car with the roof bars on however I have the aero bars which are claimed to be more aerodynamic etc. The Altea wasn't a particularly quiet car anyway.
The biggest difference I noticed was when you have the bikes on your fuel consumption is absolutely hammered - I could go from 43mpg to about 32mpg just by putting the bikes on the roof. Obviously more of an issue when travelling at speed as opposed to around town.
I didn't tend to leave the roof rack on when I wasn't using the bikes - I had mastered a technique with my son where the roof rack could be lifted on and put into place in a matter of minutes.
Re cycle carriers, again I used Thule because I got an offer when I bought the four with the bars so they are good, solid and can be locked. However I think any decent cycle carrier would suffice as all they are doing is clamping over a horizontal bar.
Re the cost, I will let you know once I have got the replacement part in to fit my Hyundai because until I take the fitting apart I don't want to say for definite that its all there. It should be , there is no reason why it shouldn't but just want to wait till I have stripped it down.
Cheers
