Slight front seat rocking/knock?

[Toothy]

Both my front seats have an ever so slight rock to them if you move your body weight about, in a certain direction. It's barely audible and very slight. I tend to notice as I get in or out the car.
I've taken a look at the bolt between the floor and rails and it's fine. Appears to be the mechanism/rails to the seat that have a slight amount of play.
Question is, is that normal? Has anyone else noticed it?

[emjay82]

Having changed my seats, there is a surprising amount of flex in the seat rails, far from rigid. I would say it's normal but interested to get other opinions. 

[kieron1977]

Yep my front seats move around a tiny bit too. 

[Stuno1]

Mine did this and Lexus Woodford checked it over and said the seat rails were tight enough and there was nothing they could do. 

[Toothy]

Thanks for the responses guys, great to hear I'm not alone with this.

[mrfunex]

I suppose mine does this a bit too. It used to creak (solved by tightening the bolts you mentioned on the front and back of the seat rails), but there's still a bit of movement. 

I'd assumed I was carrying a bit extra holiday weight...