One car addict will be upset by this! (4,8)

I believe the answer is:

road accident

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'be upset by this' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'one car addict' is the wordplay.
'one car addict' anagrams to 'ROAD ACCIDENT'.
But, I'm not clear how the anagram is indicated.

'will' is the link.

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I've seen this clue in The Irish News.

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