Click in steering wheel?

Hi! I mount curbs often, about 3-4 times a day and do it very slowly to avoid knocking the tracking out. My road is also littered with speed bumps and there is no way to avoid them.

Recently I've noticed that when I do a three point turn, the steering wheel thumps or clicks and you can physically feel it through the wheel. Any idea what this could be? The cars only done 18,000 Miles.
 
I have what sounds like the exact same problem, garage couldn't find anything wrong apart from a slightly loose steering arm which was replaced but still have the problem. Hoping its not a steering rack issue :S
 
Mine's done something which sounds like this since I bought it nearly 3 years ago approaching full lock at slow speeds - had it checked and no issues found. I just ignore it - hasn't changed, worsened or affected the performance of the car.
 
Have you tried tightening the nut near the carpet? This is what was wrong with mine when it was clunking.
 
If someone could post a guide on this, would be appreciated. Seems to be getting clunkier when it happens. It's more of a thump now than a click.
 
Im sure you can see the bolt from the drivers seat. Turn the wheel which turns a bar, the bolt is on that bar just before it goes in the floor.
Jack the car up and give the wheel a shake by pulling on the top and bottom to check the hub steering bearing things. They are weak on these cars.