To the West End, a fast model goes like a bullet! (6)

I believe the answer is:

tracer

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

I can't explain the rest of the clue.

(Other definitions for tracer that I've seen before include "One finding" , "Bullet whose track can be seen - element tracking radiation" , "Projectile" , "Missile" , "Kind of bullet that leaves trail" .)

I've seen this clue in the Evening Standard.

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