Try upping the frequency of your training, but cut down the lenghth of the sessons down to 45 minutes.
Front squats will work much better than regular squats in terms of activating your quads, but its hard to balance and you can't lift as much weight, any type of squat is going to activate your glutes really though.
you could do sessions where you pre-exhaust with them with 6-8 sets of leg extensions and do very high reps, drop sets, negatives etc. and then use 135lbs when you squat but try and go as slow as possible and keep all of the tension in your thighs, don't go ass to grass and don't be explosive out of the "Hole" of the squat because you will loose the tension in your quads and the glutes and hamstrings will take over.
just my thoughts anyways, ive always had a massive ass and just come to terms with it now. ahah.
Good luck though bro.