Old post, but hopefully this will help someone:
The human body wants to do things the easiest way possible. If your quads are naturally strong, your body will go to them first.
You need to develop a mental connection w/ your glutes. When you step under the bar, close your eyes and concentrate on your glutes, flex and squeeze them to develop "feel." Then unrack and go. Try and only take 2 steps to get into position, and maintain mental focus on your butt.
You are not going to use a lot of weight, just yet, instead concentrating on "feel." Once the connection is developed, then work up in weight. Eventually, you should be doing at least 1.5 your bodyweight for 3 sets (not counting warmup) of 5 reps below parallel. When doing lunges, step out as far as possible, keep weight on heels, and shoulders directly over hips.
Another thing, muscles do not grow while training. Training is the stimulus for growth, but growth happens while resting/eating/sleeping. If you train legs twice a week they will not get sufficient rest for growth. Train them once every 6 or 7 days, no more.
After training legs, boatload the food in. Protein/carb drink immediately after training, huge dinner, then another protein drink before bed. Have lots of protein for breakfast.