Hertz essentially opposed to driving on the left behind bike (14)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

PER SE (essentially) + CON (opposed to) + D (Driving on the left) under (behind) CYCLE . D=driving (my first attempt at parsing) isn’t sanctioned by Chambers, but of course ‘driving on the left’ is telling us to take the first letter – ie, the one furthest to the left of the word