Physical consequence of being let out in fast car? (3,3)
I believe the answer is:
jet lag
'physical consequence' is the definition.
(physical effect of changing time zones)
'let out in fast car?' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'in' is an insertion indicator.
'fast car?' becomes 'Jag' (short for Jaguar).
'let' anagrammed gives 'etl'.
'etl' put into 'jag' is 'JET LAG'.
'of being' acts as a link.
(Other definitions for jet lag that I've seen before include "Delayed physical effects felt after long aircraft flight" , "Tiredness after long plane trip" , "'Physical effects of a long flight (3,3)'" , "Exhaustion after air travel" , "Malaise caused by air travel" .)