Sharp part they oddly found on bottom of car (6)
I believe the answer is:
bitter
'sharp' is the definition.
(thesaurus)
'part they oddly found on bottom of car' is the wordplay.
'part' becomes 'bit' (both mean a piece of something).
'oddly' indicates alternate letters (letters in the odd-numbered positions are used).
'found on' says to put letters next to each other.
'bottom of' suggests the final letters.
The final letter of 'car' is 'r'.
The alternate letters of 'they' are 'te'.
'bit'+'te'+'r'='BITTER'
(Other definitions for bitter that I've seen before include "Acrid - beer" , "Act nervously" , "Dry ale in the UK" , "Acerbic" , "Intensely cold, beer" .)