Expensive car, with two on board touring becoming grumpy (9)
I believe the answer is:
irritable
'grumpy' is the definition.
(I've seen this before)
'expensive car with two on board touring' is the wordplay.
'expensive car' becomes 'rr' (short for Rolls Royce).
'with' means one lot of letters go next to another.
'two' becomes 'II' (Roman numerals).
'on board' becomes 'table' (both can mean food. I am not sure about the 'on' bit.).
'touring' indicates putting letters inside (touring can mean going round).
'ii' put next to 'table' is 'iitable'.
'rr' put inside 'iitable' is 'IRRITABLE'.
'becoming' is the link.
Can you help me to learn more?
(Other definitions for irritable that I've seen before include "snappy" , "Testy" , "Cantankerous" , "Bad-tempered" , "Fractious" .)