Bolt to fix Don's cab (7)
I believe the answer is:
abscond
'bolt' is the definition.
('abscond' can be a synonym of 'bolt')
'fix don's cab' is the wordplay.
'fix' is an anagram indicator.
'dons'+'cab'='donscab'
'donscab' with letters rearranged gives 'ABSCOND'.
'to' is the link.
(Other definitions for abscond that I've seen before include "Do a bunk" , "cut and run" , "scarper" , "Flee" , "Run away secretly" .)