I know you said it's been an ongoing thing with your knees so I'm sure you've tried about everything but do you foam roll daily? My knee felt awful for about a year anytime I drove or lifted or played ball the turning point was when I started to foam roll the quads/it band/hammies 2x a day. Now I only feel it when trying to warm up completely cold or when driving real long distances.
I also bought these bands and did the stuff from this video 1-2x a week
http://www.mobilitywod.com/2012/05/v...oral-pain.html
again you've probably done tons of stuff but anecdotally this is what really helped me