Here's a series of clips I found on various Youtube posts, and I simply saved them and edited them together for convenience.
The "hiphop remix" one is pretty clever, and the bumpers shown here lasted for several years.
There are two Looney Tunes promos from Nickelodeon that still elude us...the "Definition of Looney" ad ("That's right folks! Now we're looney tuney!") There was also an ad for "More of the Looney Tunes you want to see, and no more Bosko. Sorry, Bosko!" If anyone runs accross those two gems, let us know!