I know this may sound weird, but there probably is a reason Disney has not already sued.
Perhaps it might be too much of a hastle. Supposedly, this only a rumor mind you, "The Wild" was being worked on years ago, and then for one reason or another, they stopped for a little while. Then Dreamworks found out about Disney's film, so they rushed out the sub par, in my opinion, "Madagascar" flick. So why doesn't Disney sue? I don't know.
I just saw an ad in the brand new November 2006 edition of Disney Adventures magazine. It advertises a card role playing game called "Pirates." Maybe you've seen it. It is a special edition version of this game called "Davy Jones' Curse" and it has a picture of a game piece that is a Kraken-like squid sea monster attacking a ship. It is made by a company called Wizkids, which I don't believe is associated with Disney. Why doesn't Disney sue?
These companies, like this car movie we are talking about, must make their product just ever so different, so it is techinically their own and Disney can't sue. I know it's pretty lousy, but I guess that is just the way it is.