4x4 Dyno in NE or Yorkshire

[audidriver79]

Just decided that after 4 years of owning a 2003 RS6 that I have a desire to know the BHP. Should be 444 originally but mine has been remapped but after all this time and TLC should it be respectable? I know its a big lump of a dinosaur and it feels fast but I would just like to set my mind at rest with a reliable dyno run or two. Many thanks in advance my fellow PH'ers.