Pitch you're an absolute star 
That is how recessed the drivers headlight is with the passengers being slightly further forward (ie less gap). Damn I don't know what to do now.... *off to research how the headlights are adjusted now and maybe this is not really a cause for concern*
If they are actually different from one side to the other, then you need to ask some hard questions.
The actual headlamp assemblies do not 'drift out of alignement' with the body panels.
And for correct adjustment of the assemblies - for halogen headlamps, it is front bumper off to access the mounting adjusters, but if it has factory fit Bi-Xenons, OR halogens with the winter pack, then you can adjust them without removing the front bumper. You just need to carefully pry out the filler piece next to the headlamp washers.
HTH