An accelerator operated from the back seat (4)

I believe the answer is:

spur

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

'back seat' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for spur that I've seen before include "Hurry up" , "Prompt" , "Inducement" , "Provoke" , "This provokes sudden movement!" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.