There are a number of aero engined specials in the UK , possibly even an increasing one . The owners I have talked to at VSCC races and hillclimbs are endearingly bonkers, and think nothing of (perfectly legally ) driving their monstrous GN Thunderbug or Bentley Napier cross country on public roads to compete .
Some folk love to moan about what an over legislated country we are - but we should celebrate the fact that a chap can drive his flame spitting , chain driven , massively polluting , seat belt free car in the UK . One chap I;'ve interviewed even takes his Theophile Schneider on the ferry to France and then drives the route of the 1906 French GP