Front suspension knocking over bumps

[Dubai_Andy]

Since I bought my X5 back last June, it's been to the garage five times - three of which have been to try and fix a knocking that I get from the front suspension when going over bumps. The garage tells me that they've completely stripped the front end, checked all components and replaced ALL the bushes. Still, the knocking continues...

I live out in Dubai and to be honest, I can't say that I trust the workmanship when I compare to garages in the UK... anyway, I've got 3000km left on my warranty and I WANT IT FIXED!

The knocking happens over any bumps. For example, when the car first meets a speed bump there will be a knock. If I drive the car on an uneven non-tarmac track the knocking will be near continuous. There is clearly a fault, yet the garage say that they cannot locate it.

The knocking seems to be fairly central in terms of where the sound comes from... not really left or right. Aside from the knocking, the front right air strut was replaced a few months ago and the front left has just started to leak a bit too (sometimes the car is very low on the one side in the mornings and the ride height light has come on a few times). Could this be related?

Any things to check out, or any tests to identify the fault would be much appreciated.

Would taking a video with sound help?

Thank you for any help you can offer.

Andy