Aid for driving glitzy dandy about (3,4)
I believe the answer is:
fog lamp
'aid for driving' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'glitzy dandy about' is the wordplay.
'glitzy' becomes 'glam' (I can't explain this - if you can you should believe this answer much more).
'dandy' becomes 'fop' (synonyms).
'about' is an insertion indicator.
'glam' put within 'fop' is 'FOG-LAMP'.
Can you help me to learn more?
(Other definitions for fog lamp that I've seen before include "It improves visibility" , "shines amid the gloom" , "Bright light used in poor driving conditions" , "Driver's visibility aid in mist" , "Strong car headlight" .)