If you just slather on anything, it could be bad to have all that excess. Not to mention slinging it everywhere once you move!
I try to just wash new tires until that doesn't "do it" anymore; and if the color of the tires starts to get patchy I'll use a shine product, bu wipe the tire down with an old shop rag. You end up with a more uniform look...
And if you're driving the hell outta your car; the tires won't have so much time as to dry-rot or become damaged from a shine product.
Coal Country Cruise... YOU MISSED IT!!! Pics here: http://www.focusfanatics.com/forum/showthread.php?t=296590&page=2