Train as mobile mechanic, say (7)
I believe the answer is:
artisan
'mechanic say' is the definition.
(mechanic is a kind of artisan)
'train as mobile' is the wordplay.
'mobile' is an anagram indicator.
'train'+'as'='trainas'
'trainas' anagrammed gives 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Handy worker" , "Skilled craftsperson" , "crafty person?" , "craftsman of his trade" , "Train as (anag) - craftsman" .)