Same here, ever since I've been having the geo done by WIM no problems at all. Just had new rear tyres fitted at WIM last week, and a geo after 3 years, geo was slightly out understandably but front tyres have perfectly even wear, and still have about 4-5mm on them after 20k miles.
I would highly recommend getting your car to WIM or one of its approved centres (there's a map of them on their website) to get your car set up correctly - hate to be negative but I can't see the battle against Lexus UK going anywhere in particular.