First a little about my game. I am a high handicap player still trying to break 100. My short game is getting pretty good, when I use my PW it is like throwing a lawn dart onto the green. The problem lies within my long game/ tee shot. My drive will go for about 100 yards beautifully straight but then, makes a wicked 90 degree turn to the left (I am a lefty in case you didnt realize by my handle) as if it were on rails...

I previously posted for help which I did recieve. The grip change and exercises help alot on my iron play, but still causing extremely frustrating tee shot bananna balls. Ive spent countless hours at the range using my driver from normal swings to very slow swings, all with the same result. Thru the help of some friends and other players the common consensus is that my drivers hold to much flex for my swing which keeps the face open. I realize that they are probably right because when I hold the club out directly in front of me and shake it, i can see and feel the wobble.
Im to the point of, going out and buying a new driver with less flex in the shaft. Is there any exercises or tips im missing or am I just better off getting the new driver?