Oops.

time for a new filter i think.....

...definitely. It was replaced only three weeks ago, but clouds of dust came off when I hit it with my hand.

Salisbury Plain was very dusty.

i would assume keeping an old "Clean" one would be beneficial for those dusty tracks......

My wife's old Td5 D2 had an inch of dried mud in the airbox after I waded through some very muddy water. It didn't cause any problems over the subsequent 30K miles we had it. When the airbox of her D4 was filled with moss by mice it more-or-less crippled it - the get-up-and-go got-up-and-went.

A raised air inlet would help with that. It's intended to take cleaner air from above the dust plume coming off the wheels. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed