I was never a concours/keep it stock guy. To each their own.
Form follows function sounds logical, but IMO good design STILL depends on harmony/balance, and beauty ....well, is defined by a lot of individual factors.

That spoiler lip is too much for my taste. Someone get me my Photoshop...voila...better now. BALANCED
Edit: Fender flares and (wide) body kits are not really my cup of tea...that's why I had to photoshop them, too.