What is best way to reduce or eliminate the wind disturbance noise I get when driving my '12 TL over 45mph with sun roof open? Is it as simple as adding the stock TL deflector?

 

Just crack the rear windows about a 1/4 inch. Noise goes away.

 

You can also try this. Open the roof until all but approx 4-5 inches of the sunroof is showing and the rest is hidden and then adjust it as you drive if you feel you need more wind buffeting.

This usually works best for me at highway speeds when all windows are up.

 

Yes, the sunroof deflector will also eliminate some wind noise.

 

I missed the OP asking about the deflector in his post, I forgot about those. Yup they definitely work had one on the first MDX I owned, worked well.

Actually I haven't seen / noticed one of those on a car lately.

 

Sunfroof deflector does work but it's not the prettiest thing. Cracking the rear windows is my remedy.