When I hit about 35-40 mph, I'm getting a lot of wind noise from the drivers side window ...like the window is cracked open a little. No noise on the passenger or rear windows.

Is there a cheap/quick fix?

 

I have the same problem with mine, but it is actually coming from the base of the windshield, not the driver's side door (though it sounds like it). Haven't come up with a solution for it yet.

Is the window actually going all the way up? You should be able to run your finger (or a pen, something small) along the inside of the seal and lift it back to see if the window is all the way up.

You could also check around your mirror on the outside, see if it's loose from the door itself.

 

Also check your door seal for leaks or tears.

 

I have seen rolls of foam tube inserted into the cavity of the weather strip. This firms up the weather strip not allowing it to collapse in as easily.
Might be worth a try. Good luck