Like others have said, some negative camber is normal and by itself won't hurt the tires or anything else, but the thing to watch for is tire wear. If the inside of your tires start to wear, that means your toe is out of spec, and it'll chew through tires like nobody's business. Mine went through a pair of $250 Continentals in less than a year; cords were showing on the inside of both of them. I replaced a bunch of rear end components that were probably original, had it aligned, and it's all good. But it still has a bit of negative camber. No big deal.

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2001 X5 Sport 3.0/5-speed
1998 318ti/5-speed
1988 735i/5-speed
1984 528e/5-speed (soon to be M20B25-powered 525i!)