This was one of the Concours D'Elegance entrants at the VSCC's Boulogne and Hawthorn Trophies Race Meeting at Oulton Park in May 2005.
It's Mark Clark's 20hp 1907 Stanley Steamer H5 but, apart from a list of the Concours entrants, there's no mention of it in the programme of the meeting.
I came across the car being driven round the paddock a couple of times during the day.
The chassis number is 3708, and it's listed here in the Stanley Register Online. In September 2007 it took part in an 40 mile run of Edwardian cars from Donington Park, and on 17 March 2016 I showed a photograph that I took in the paddock on that occasion.