2014 S with about 36,700 miles on it:

Whenever the car is driven after a cold start/it's been off for a while, there's a clicking sound when I hit about 30mph. I don't know how to describe it, almost like a very faint reloading sound of a gun. It seems like it's coming from the underbody, maybe near the middle I dunno. Every time. I've noticed it in the past 2-3 weeks. It's most noticeable only when the car is driven after being off overnight for example, but a little noticeable if the car has been off for 15-30 mins even (before being driven again).

Hit 15mph, the door locks locked like they should automatically and then it hits about 30 and there's that clicking noise from the underbody.

Took it to dealer, they can't seem to replicate it. I know it's there, I notice it every day I take it in the morning. Heck, even today when I drove it first to get there.

Anyone have any idea what the cause could be? Once the car has been driven past 30, the sound doesn't happen again even when I get to a standstill at a red light for example and drive again. So it's something mechanical I feel that that's tied to the car being off for a while, but not sure what the magic is around 30mph.

 

its you abs pump , its normal thats how it checks itself

 

If it's a clicking sound I don't know what that could be however if it's more of a thump or knock which happens only once it's probably the abs self check mechanism. If so, it's totally normal. My car does it as I pull out of my driveway and accelerate. Now that I think about it, that's more than likely what you're hearing.