Told to buy car, bottle opener and antacid (6)

I believe the answer is:

bicarb

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

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

'told to buy car bottle opener' is the wordplay.
'told' indicates a 'sounds like' (homophone) clue.
'bottle opener' becomes 'b' (I can't justify this - if you can you should give a lot more credence to this answer).
'buy' is a homophone of 'bi'.
'bi'+'car'+'b'='BICARB'

'and' is the link.

Can you help me to learn more?

(Other definitions for bicarb that I've seen before include "Digestive remedy (abbr)" , "Baking soda (colloq.)" , "Baking soda (abbr)" , "Antacid" , "It helps digestion" .)

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

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.