Quirk of taxing Formula One scrap, keeping heat right up (6,4)
I believe the answer is:
fiscal drag
'quirk of taxing formula' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'one scrap keeping heat right up' is the wordplay.
I cannot really understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
'scrap' could be 'rag' (I've seen this before) and 'rag' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for fiscal drag that I've seen is " windfall for the Treasury".)