Drive away to enter plain and go too far? (9)
I believe the answer is:
overshoot
'go too far?' is the definition.
(to overshoot is to go past)
'drive away to enter plain' is the wordplay.
'drive away' becomes 'shoo' (shooing is a kind of driving away).
'to enter' indicates putting letters inside.
'plain' becomes 'overt' (I've seen this in another clue).
'shoo' going within 'overt' is 'OVERSHOOT'.
'and' is the link.
(Other definitions for overshoot that I've seen before include "Taxi too much, perhaps" , "Go beyond the intended target" , "Go too far" , "Go extra distance" , "Go beyond the mark" .)