The most common and most likely answer to this crossword clue is the 5 plus 4 letter word MOTOR SHOW
I've seen this crossword clue in The Daily Telegraph
M
O
T
O
R
S
H
O
W
Buddy explains!
The straight part
We know that "what took place at Earls Court" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what took place at earls court = motor show.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.