I agree with most in this string - the paint durability on my '02 IS 300 is terrible. I've had mine just over a year and it has far more paint chips than any other car that I've owned. I have a VW Golf as well, with five times as many miles on it, and it has just a few paint chips on its front end.
I have also asked the dealership and Lexus about this, but got the runaround from both. The same "because the front end is slanted" excuse was given. Logic says to me that a flatter, more square front end would get more chips, as it creates an opportunity to create a more direct hit that would cause damage.
It's embarrassing to spend $30k plus on a brand with a reputation for quality and get this. Makes me want to consider a G35 or S4 next time around.