If your talking about a gentle drift to the left, this is completely natural on any car that spends most of its life on a cambered road, even on a flat car park surface, your car may still drift to the left, LHD cars will drift to the right!
Before you make any changes, you must start with the basics, otherwise its all a complete waste of time and money
1 Your front tyres must be in perfect condition, and inflated to the correct pressure, and have equal tread, one tire at 8k miles, and the other at 12k miles it not good enough!
if your tyres are directional, make sure they're fitted the rotation correct! also same brand per axle is essential
2 check that you havn't got broken springs! Shot shock absorbers, will not cause drifting, unless braking. also check brake calipers are not sticking.
3 Drive your car in a straight line, firmly holding the steering wheel, is the steering wheel in straight ahead position? if not, either get the tracking adjusted so it is, or refit the steering wheel
If your still not happy, then you have to start replacing,bushes and bearings etc
Tom