It wasn't a dumb song, just a dumb execution
You could make a good country/rap crossover if you take the best elements of rap (the beat and good lyrics, which disqualifies Nelly) and country (storytelling, not to say rap doesn't do that as well though). Instead their song took the worst elements of rap (primarily repetition ad nauseum) and the only "country" thing about it was the acoustic guitar
I too would add my vote for "My Humps", especially considering the woman singing it has no humps (or any figure) at all