when i had my mk6 escort it would kill the inside edge of the tyres, down to the cords in about a month...

in the end i drilled out the ball joint, cut the arm down, had some plates welded on and drilled so that the ball joint was about 20mm further in. (from the pics it looks like there was another hole that i used and redrilled the outermost hole)
They were also polybushed and seemed to sort it out.