Make car skid into swimmer's endpiece (8)

I believe the answer is:

fishtail

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'make car skid into' is the definition.
I can't judge whether this definition defines the answer.

'swimmer's endpiece' is the wordplay.
'swimmer' becomes 'fish' (fish swim).
'endpiece' becomes 'tail' (I can't explain this - if you can you should believe this answer much more).
'fish'+'tail'='FISHTAIL'

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(Other definitions for fishtail that I've seen before include "trailer may do" , "swing the rear end" , "A skid from side to side" , "skid sideways" , "Merman's got one" .)

I've seen this clue in the Sydney Morning Herald.

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