Might consider BB Hack Squats, one of my favorite exercises. Try placing the heels on a 2X4, plates, etc for more influence on the tear drop effect of the lower quads. Touching the plates to the floor, each rep, gives a good stretch also.
I think of these as reverse DL's in a way, with the weight behind , rather than in front, of the body. But with more direct focus on the thighs. Think the record is over 700/800, if remembering right. Good Luck.