Autocar Glass Plate A5580
Looks like a 10hp Rover to me
276 was the first car - earlier numbers were motorcycles and three wheelers. Taken at the start, Bridge House Hotel, Staines.
Would that be Dudley Noble? Note the use of the double-windscreen, something modern drivers of vintage-era cars seem unaware of.
This photo was taken outside the Bridge House Hotel in Clarence Street, Staines, looking towards the town. The Exeter Run began at this location between 1911 and 1926 - and possibly before and beyond these dates, too. Some reports from local papers are available.