Hey guys, this my first thread here on 6speed.
Wish it could have been something more sexy like mods...

Today I experienced a knock coming from (what feels like) under my car just behind/below the drivers seat.

It only happens when I put my foot down to give a short burst of gas from stopped position or slower speeds (knock not present in reverse).
I'm not hearing anything but it feels like something solid stumps against the bottom (only once per acceleration), first I thought it might be some play in the seat rail but that's not it...

Since I've got a C4S could it be a loose drive shaft?

Any help would be appreciated.

Cheers,

Sid.