I am thinking about trading my 06 C2 for a new 2011 CS Cabriolet. I have never driven one and was wondering how much louder it is that the coupe with the top up? I know it will be louder with the top down but I am interesed in the differance at hyw speed with the top up.
Thanks

I have a C4S cab. It is fairly quiet at highway speed in seventh gear (PDK). Not as quiet as a coupe, but close enough for me. I do notice a high pitched whistle with the top up at 68 mph, that changes to a higher pitched whistle at about 70 mph. Very strange to hear; kind of like being piped aboard a ship. Go faster and the sound goes away. Probably too high a note for me to hear.
I NEVER thought that I would drive a cab, much less own one (see avatar). Now, I drive with the top down as often as I can --including on the highway. The wind fence that attaches behind the front seats really calms the wind.
Best wishes on your decision.

A friend of mine had a 2006 coupe w/ OEM Continental tires & his car was always louder then my '06 Cab w/ PS2 tires. For over 3 years very time he road in my car he always said how much louder his was. Both cars had almost the same options on them.

I didn't do a lot of back to back comparisons, but I don't recall the cab being much louder (if at all) than the coupe.

Another benefit of the cab is that it's like having two cars in one. With the top up, you feel like you're in a race car ****pit and the engine sound is smoother. With the top down, besides the exposure to sun and air, the car feels more spacious and engine sound is a bit more raspy (though not really louder ). And these comparisons include speeds over 100 mph.

For me, the benefits of the cab far outweigh the small reduction in performance.