Driver's seat left front mounting bolt attachment has failed. problem was first noticed on 15 march 2016. vehicle was stationary. as i was shifting around to get seated i noticed a grinding sound coming from beneath the driver's seat. eventually i observed the left front mount lifting slightly off the floor. later, investigating further (removing the plastic covering) i was able to remove the mounting bolt'there is nothing for the bolt to attach to that i can see. whatever held the bolt originally has broken off and is no longer visible or serviceable. this is a critical safety concern for me; all the more so because i was recently diagnosed with three bulging discs in my neck at the san francisco va medical center on 8 march 2016. should i be in a collision and the seat not perform as intended, i could potentially be paralyzed. this is a safety concern. toyota should be required to perform a safety recall for this problem.