under hard braking, my seat feels like it slides forward an inch or two and i can feel a clunking sound when it does that. I've check the bolts and stuff, they are tightened. is there something else i'm missed? never happen before...just started like a week ago.

 

The same thing happened to me when I had a spare tire on the floor behind me

 

Check the tracks the seat moves back and forth on. Adjust it to the position you are comfortable driving in, then move back and forth to see if it will 'clunk'. Sometimes it just needs to lock into position after you adjust it.

 

it does lock into position after i'd adjusted it. seems like something isn't locking the seat into the position so it's slippin a few notches. i just hope it doesn't get any worse.