Has anyone experience this? I can get it to consistently make a low pitched rumble noise when reversing at full lock. I'll probably bring the car in for warranty check, but wanted to see if you guys experienced this and how you remedied it.

 

Wonder if that's the electronic differential lock kicking in to prevent driveline binding (assume All4?) and thus normal. It might also be a bad CV joint but yes, without bringing it in to the dealer and having them look at it, it's all conjecture and guesswork.