I have a 2000 model which didnt come with the diffuser between the seats and it kills me that I dont have one. One, because I think it looks cool, and two, because if it actually reduces the noise in the cabin then I really might be missing out.

So does it actually reduce the noise by a significant amount?

 

A few times I have put mine down to see if it made a difference. I never noticed any change

 

I have a 2000 now and I use to have a 2002 with the deflector. In my experience I notice no difference with or without it. I like not having it now because I think it's a cleaner look. On a few side notes, I have clear plexiglass in the mesh headrest of the seats and that makes a big difference in wind noise reduction
Next, the glove box without the wind deflector holes in it is worth gold to the guys with hard tops

 

Noise? No! Wind buffeting? Barely noticeable. Don't bother with it or get the taller insert.

 

Doesn't make much noise difference in my '05, not nearly as much as raising the windows does. Tire noise, mine and others, is the main noise generator around here at anything below handcuff speeds. For a forthcoming interstate trip, I may cut a plexiglas barrier conforming to the shape and height of the roll bars, that should reduce backdraft between the seats to almost nothing.

 

Noticebly less wind buffeting with it erected

 

More wind in the lower cabin area (near center console and legs), with it lowered.

 

Already answered above several times but if you want another data point: Noise, no. Wind, yes.

 

Get one of the taller ones. Makes a big difference in the wind and wind noise.

 

God I'm immature. Made me laugh.