Every 6 months or so i have to get a wheel alignment done on my EF GLi, as it always chews out the inside edges of the tyres and pulls to the left.

I tried a few different wheel alignment places but no great improvement and they have never pin pointed any over worn components and theres plenty of camber adjustment.

Its fitted with Tickford suspension and I'm running 17" wheels, The car has done 295,000 km. In the five years i've had the car i have never replaced any suspension or steering components.

What should I look at doing to improve its ability to drive in a straight line?

If it has a kit then they have all been too slack to adjust it. Get a printout next time and I can tell you what needs to be done.

If both the insides of the tyres are scrubbing its toe out. Now the wheel alignment is done static (not driven) so what may be happening is you have either worn tie rod ends or worn rack ends. It can only take one of these to have the toe change whilst driving. I had all sorts of problems with my toe adjustment and ended up being the left rack end had about 1mm of play which could throw the toe out up to 4mm. Dont forget that tyre places arent normally mechanics so it isnt really their job to find worn or bad suspension. Pedders can do a check for you for a small cost.

It is their job. They either dont look or dont know what they are doing.

yeah post up some readings... I'm thinking your getting a dodgy wheel alignment.

And a common problem with the standard tickford suspension is the lower inner bush (which is urethane on tickfords) flogs out real easy - this gives a massive camber change and will chew out tyres.

CHeers