Originally Posted by rs2000mk5

its probably to do with bump steer and scrub circle's

bump steer= when a car is lowered the track rods are moved upwards, so when you go over a bump or uneaven road the track rod starts to pull the wheel in and efectively steers the wheel slightly=bump steer.

scrub circle= the scrub circle from what ive been told is an immaginary line on the front suspension.
viewed from the front of the car the line would run from the center of the top mount and goes through the center of the bottom ball joint and continues to run down where it SHOULD meet the center of the tyre.
when the car is lowered i think the wheels need to go out a tad to keep that line straight.
If you change the tyre size (circumfrance) you are also altering this scrub circle so be aware of this.
i recon to try and fit 5mm spacers behind your front wheels and see if that helps a tad.
if the car is lowered 30mm then in theory the steering rack should be raised 30mm which isnt possible in most cases.
try finding some track rod ends that can go on up side down, so the track rod is back to its standard horizontal position.