Andrew Walker and his wife co-founded a juice company, which includes juice made from beets. This is a fun tie-in to Johnny's passion for making juice in this movie.
While the Duke and his relatives, especially Allistair, are condescending toward Johnny about his being a mechanic, most people of all classes in the UK are actually quite proud of, and quick to point out the fact that Queen Elizabeth II was an officer, mechanic and truck driver in the British Army's Auxiliary Territorial Service during World War II.
When Allistair introduces himself as "Allistair Covington-Breed of Winshere, north of Devon," Johnny replies with, "Johnny Payne, South Philly, east of Pat's Cheesesteak." Pat's (actually Pat's King of Steaks), which began as a hot dog stand at Passyunk Avenue and 9th Street in South Philadelphia, is credited for inventing the Philly cheesesteak circa 1933.
The car that Johnny and Duke repair and take for a drive is a 1968 Triumph TR-6
One of the members of Irish rock band Eldars appears in this movie