Seat is just as solid, so in an accident it wont fall apart, used all the standard parts, just lowered the bar that controls seat height, same bolts. In effect it has lowered the front of the seat about 2 or 3cm, just enough to make it comfortable. I can not imagine it would effect anti submarining as the seat is lower at the back. Also it doesnt effect the comfort of the back of the seat as the back of the seat is pretty standard lowest setting. Im not promoting anyone to do this and I did tell my insurance company and it made no difference, just noted on policy as a modification. The only real problem is I had to relocate the sub, junked it and bought a pioneer one and that actually sounds better than the original because you can turn the base to your own requirements. I will get pics on here as soon as I can but had operation on arm, cant lift.