Grease coming from driveshaft U-joint
 

So my Z is almost out of the general warranty at 35,18x and I decided to get it checked out by a good shop.

The only thing the mechanic found was excessive grease coming from the driveshaft U-joint. He says this may be normal and I wanted to get your guys' input. Is it worth the trip to the dealer to get this looked at or is this just how it's designed?

I still have until 60,000mi for the power train to run out to get it checked, but I want to start modding ASAP and don't want to take **** from the dealer about it.