Squat Critique

[Saeger]

I need some critique on my squat. Below is a video of me hitting 275 for 6 reps, I know not very heavy. Just looking to get some advice on the weak points and get a better squat over all.

http://s1278.photobucket.com/user/saeger0411/media/20130729_125315_zpsac42c2c8.mp4.html?sort=3&o=0

[Saeger]

Also, I realize I am squating in jeans, workboots etc. I have anywhere from 20-45 minutes to fit my workouts in during my lunch break each day, so most days I am wearing my normal work clothes throughout. It doesn't bother me to much other than the occasional ripped seem after squats lol.