Formula Palmer Audi's return to Castle Combe after a four-year absence was marked by 13 drivers breaking the previous lap record in the first free practice session. Stefan, on his first visit to the Wiltshire circuit, was 10th fastest but improved to third in the second session. He then followed up by qualifying third for both of Sunday's races. Championship leader Tim Bridgman took two second places, while the two pole positions went to Jack Clarke and Tom Bradshaw.

Sunday was a grey day with periods of rain and the racing was punctuated by accidents, red flags and delays. The first FPA race - Round 12 - was declared wet and was full of incident, with several drivers putting a wheel or two on the grass or cutting chicanes. There was also a safety car period after Jolyon Palmer crashed out into a tyre barrier when trying to overtake. Some drivers made up a number of positions while others lost them - Stefan was one of the losers, coming home in seventh place. Tim Bridgman won the race after snatching the lead at the start.

Round 13 began much later than scheduled so the number of laps was reduced, but the race was, if anything, even more action-packed. On the by now dry track Stefan jumped straight into the lead, only to see the race immediately red-flagged following a start-line collision. There was another red flag two laps after the restart when Bradshaw and Palmer collided, and the laps were reduced again. At the second restart it was Bridgman who took the lead, followed by Clarke. Stefan made good use of his boost button to pass first one, then the other, powering round the outside of Bridgman as rain started to fall. The race was red-flagged for good when three more cars went off the track and Stefan, still pushing hard, took his second win of the season.

In the championship, Bridgman extended his lead but Stefan cut the gap to Luciano Bacheta to just three points.