It costs a lot of money to buy Lego. Or to buy books, DVDs, music downloads, etc. What's the difference between that and modding a car? Everyone needs an outlet or hobby to spend money on.
So yeah, I agree with 5150 Lego. But, like I said, some mods are over-the-top. In this case I would agree with Optimax.
Can you tell I'm trying to be the voice of reason and diplomacy here? ;-)
On a side note, I was looking at some VW Beetles (original) today, on the way to my grandmas. Someone had done them up and painted them in different styles- bumblebee stripes, dark pink and Herbie were on show. Interesting...