hopIQ found 10 beers with the same clean and crisp character as Spitfire Lager. Shepherd Neame's lager detour — a pale lager with full body but discreet hopping (only 14 IBU), a vanilla note up front per the brewery's Cyclops descriptor. The name Spitfire refers to the RAF fighter of the Battle of Britain — the Faversham brewery sits in the heart of Kent, where the Spitfires were stationed. The Amber Ale sibling is better known, but this lager has its own following. Ranked by flavour match rather than popularity.
Closest match: Steinbach Bräu Storchenbier — 71%. No twin in the catalogue yet.
4 countriesmatched across 56 flavour tagsbest match 71%

No beer in the catalogue yet — these come closest.
Close on what matters, with one thing they do differently.
Same idea, less detail — open a beer to see the full comparison.