He's reluctant to pay for faultless service on the motorway (5)
I believe the answer is:
miser
'he's reluctant to pay' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'faultless service on the motorway' is the wordplay.
'faultless service' becomes 'ser' (I can't explain this - if you can you should believe this answer much more).
'on' is a charade indicator (letters next to each other).
'the motorway' becomes 'MI' (resembles Ms, English motorway).
'ser' after 'mi' is 'MISER'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for miser that I've seen before include "Curmudgeon" , "One doesn't spend much" , "Cheapskate" , "Mean individual" , "One of the people who spend least" .)