It might be, but I doubt it will be noticeable. Couple things:
1) what color is the car? If it does oxidize it will more noticeable on darker colors. If you are white or silver I would say don't worry.
2) if it is off-color then you could probably use a clay bar, or some buffing compound, to get the colors to match a little closer.
<span style='color:green'>Nobody likes you.</span><img src='http://www.bmw-forums.com/forum/html/emoticons/ph34r.gif' border='0' alt='user posted image' />
<span style='color:green'>Are you experienced, little girl? I want to know what goes on in your little girl world.</span>
<span style='color:green'>I'm the man! I'm bad, I'm so bad I should be in detention. I'm the man!!!</span>