A big thing in car production? (6)

I believe the answer is:

bumper

I'm a little stuck... Click here to teach me more about this clue!

'a big' is the definition.
(I've seen this before)

I don't understand how the remainder of the clue works.

(Other definitions for bumper that I've seen before include "generous amount of alcohol" , "end on a car" , "Protective vehicle bar" , "bar that can absorb impact of crash" , "bouncer" .)

I've seen this clue in the Evening Standard.

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